Merge branch 'master' into Basilisk-releasev2018.09.05

90 files changed, 213 insertions, 930 deletions

diff --git a/dom/base/Navigator.cpp b/dom/base/Navigator.cpp
index ed96ee23b..1bc4f82f4 100644
--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -684,8 +684,6 @@ Navigator::GetDoNotTrack(nsAString &aResult)
 bool
 Navigator::JavaEnabled(ErrorResult& aRv)
 {
-  Telemetry::AutoTimer<Telemetry::CHECK_JAVA_ENABLED> telemetryTimer;
-
   // Return true if we have a handler for the java mime
   nsAdoptingString javaMIME = Preferences::GetString("plugin.java.mime");
   NS_ENSURE_TRUE(!javaMIME.IsEmpty(), false);
diff --git a/dom/base/nsDOMClassInfo.cpp b/dom/base/nsDOMClassInfo.cpp
index d125e5ad1..1cfde6e1b 100644
--- a/dom/base/nsDOMClassInfo.cpp
+++ b/dom/base/nsDOMClassInfo.cpp
@@ -49,7 +49,6 @@
 #include "nsContentUtils.h"
 #include "nsIDOMGlobalPropertyInitializer.h"
 #include "mozilla/Attributes.h"
-#include "mozilla/Telemetry.h"
 
 // Window scriptable helper includes
 #include "nsScriptNameSpaceManager.h"
@@ -1903,9 +1902,6 @@ LookupComponentsShim(JSContext *cx, JS::Handle<JSObject*> global,
                      nsPIDOMWindowInner *win,
                      JS::MutableHandle<JS::PropertyDescriptor> desc)
 {
-  // Keep track of how often this happens.
-  Telemetry::Accumulate(Telemetry::COMPONENTS_SHIM_ACCESSED_BY_CONTENT, true);
-
   // Warn once.
   nsCOMPtr<nsIDocument> doc = win->GetExtantDoc();
   if (doc) {
diff --git a/dom/base/nsDOMNavigationTiming.cpp b/dom/base/nsDOMNavigationTiming.cpp
index 32ce8a8cb..9c732f2d8 100644
--- a/dom/base/nsDOMNavigationTiming.cpp
+++ b/dom/base/nsDOMNavigationTiming.cpp
@@ -15,7 +15,6 @@
 #include "nsPrintfCString.h"
 #include "mozilla/dom/PerformanceNavigation.h"
 #include "mozilla/TimeStamp.h"
-#include "mozilla/Telemetry.h"
 
 using namespace mozilla;
 
@@ -203,12 +202,6 @@ nsDOMNavigationTiming::NotifyNonBlankPaintForRootContentDocument()
                            mDocShellHasBeenActiveSinceNavigationStart ? "foreground tab" : "this tab was inactive some of the time between navigation start and first non-blank paint");
     PROFILER_MARKER(marker.get());
   }
-
-  if (mDocShellHasBeenActiveSinceNavigationStart) {
-    Telemetry::AccumulateTimeDelta(Telemetry::TIME_TO_NON_BLANK_PAINT_MS,
-                                   mNavigationStart,
-                                   mNonBlankPaint);
-  }
 }
 
 void
diff --git a/dom/base/nsDeprecatedOperationList.h b/dom/base/nsDeprecatedOperationList.h
index 8fb381d9d..ea4b05289 100644
--- a/dom/base/nsDeprecatedOperationList.h
+++ b/dom/base/nsDeprecatedOperationList.h
@@ -44,7 +44,6 @@ DEPRECATED_OPERATION(PannerNodeDoppler)
 DEPRECATED_OPERATION(NavigatorGetUserMedia)
 DEPRECATED_OPERATION(WebrtcDeprecatedPrefix)
 DEPRECATED_OPERATION(RTCPeerConnectionGetStreams)
-DEPRECATED_OPERATION(AppCache)
 DEPRECATED_OPERATION(PrefixedImageSmoothingEnabled)
 DEPRECATED_OPERATION(PrefixedFullscreenAPI)
 DEPRECATED_OPERATION(LenientSetter)
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 8acfd901a..ac9601caf 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -25,7 +25,6 @@
 #include "plstr.h"
 #include "mozilla/Sprintf.h"
 
-#include "mozilla/Telemetry.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsILoadContext.h"
@@ -12370,101 +12369,7 @@ MightBeAboutOrChromeScheme(nsIURI* aURI)
 void
 nsDocument::ReportUseCounters()
 {
-  static const bool sDebugUseCounters = false;
-  if (mReportedUseCounters) {
-    return;
-  }
-
-  mReportedUseCounters = true;
-
-  if (Telemetry::HistogramUseCounterCount > 0 &&
-      (IsContentDocument() || IsResourceDoc())) {
-    nsCOMPtr<nsIURI> uri;
-    NodePrincipal()->GetURI(getter_AddRefs(uri));
-    if (!uri || MightBeAboutOrChromeScheme(uri)) {
-      return;
-    }
-
-    if (sDebugUseCounters) {
-      nsCString spec = uri->GetSpecOrDefault();
-
-      // URIs can be rather long for data documents, so truncate them to
-      // some reasonable length.
-      spec.Truncate(std::min(128U, spec.Length()));
-      printf("-- Use counters for %s --\n", spec.get());
-    }
-
-    // We keep separate counts for individual documents and top-level
-    // pages to more accurately track how many web pages might break if
-    // certain features were removed.  Consider the case of a single
-    // HTML document with several SVG images and/or iframes with
-    // sub-documents of their own.  If we maintained a single set of use
-    // counters and all the sub-documents use a particular feature, then
-    // telemetry would indicate that we would be breaking N documents if
-    // that feature were removed.  Whereas with a document/top-level
-    // page split, we can see that N documents would be affected, but
-    // only a single web page would be affected.
-
-    // The difference between the values of these two histograms and the
-    // related use counters below tell us how many pages did *not* use
-    // the feature in question.  For instance, if we see that a given
-    // session has destroyed 30 content documents, but a particular use
-    // counter shows only a count of 5, we can infer that the use
-    // counter was *not* used in 25 of those 30 documents.
-    //
-    // We do things this way, rather than accumulating a boolean flag
-    // for each use counter, to avoid sending histograms for features
-    // that don't get widely used.  Doing things in this fashion means
-    // smaller telemetry payloads and faster processing on the server
-    // side.
-    Telemetry::Accumulate(Telemetry::CONTENT_DOCUMENTS_DESTROYED, 1);
-    if (IsTopLevelContentDocument()) {
-      Telemetry::Accumulate(Telemetry::TOP_LEVEL_CONTENT_DOCUMENTS_DESTROYED, 1);
-    }
-
-    for (int32_t c = 0;
-         c < eUseCounter_Count; ++c) {
-      UseCounter uc = static_cast<UseCounter>(c);
-
-      Telemetry::ID id =
-        static_cast<Telemetry::ID>(Telemetry::HistogramFirstUseCounter + uc * 2);
-      bool value = GetUseCounter(uc);
-
-      if (value) {
-        if (sDebugUseCounters) {
-          const char* name = Telemetry::GetHistogramName(id);
-          if (name) {
-            printf("  %s", name);
-          } else {
-            printf("  #%d", id);
-          }
-          printf(": %d\n", value);
-        }
-
-        Telemetry::Accumulate(id, 1);
-      }
-
-      if (IsTopLevelContentDocument()) {
-        id = static_cast<Telemetry::ID>(Telemetry::HistogramFirstUseCounter +
-                                        uc * 2 + 1);
-        value = GetUseCounter(uc) || GetChildDocumentUseCounter(uc);
-
-        if (value) {
-          if (sDebugUseCounters) {
-            const char* name = Telemetry::GetHistogramName(id);
-            if (name) {
-              printf("  %s", name);
-            } else {
-              printf("  #%d", id);
-            }
-            printf(": %d\n", value);
-          }
-
-          Telemetry::Accumulate(id, 1);
-        }
-      }
-    }
-  }
+/* STUB */
 }
 
 void
diff --git a/dom/base/nsFrameMessageManager.cpp b/dom/base/nsFrameMessageManager.cpp
index 6fffd376b..f173678b7 100644
--- a/dom/base/nsFrameMessageManager.cpp
+++ b/dom/base/nsFrameMessageManager.cpp
@@ -32,7 +32,6 @@
 #include "mozilla/CycleCollectedJSContext.h"
 #include "mozilla/IntentionalCrash.h"
 #include "mozilla/Preferences.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/dom/File.h"
 #include "mozilla/dom/MessagePort.h"
 #include "mozilla/dom/nsIContentParent.h"
@@ -716,9 +715,6 @@ AllowMessage(size_t aDataLength, const nsAString& aMessageName)
   NS_ConvertUTF16toUTF8 messageName(aMessageName);
   messageName.StripChars("0123456789");
 
-  Telemetry::Accumulate(Telemetry::MESSAGE_MANAGER_MESSAGE_SIZE2, messageName,
-                        aDataLength);
-
   // A message includes more than structured clone data, so subtract
   // 20KB to make it more likely that a message within this bound won't
   // result in an overly large IPC message.
@@ -727,9 +723,6 @@ AllowMessage(size_t aDataLength, const nsAString& aMessageName)
     return true;
   }
 
-  Telemetry::Accumulate(Telemetry::REJECTED_MESSAGE_MANAGER_MESSAGE,
-                        messageName);
-
   return false;
 }
 
@@ -2248,7 +2241,6 @@ nsSameProcessAsyncMessageBase::Init(const nsAString& aMessage,
                                     nsIPrincipal* aPrincipal)
 {
   if (!mData.Copy(aData)) {
-    Telemetry::Accumulate(Telemetry::IPC_SAME_PROCESS_MESSAGE_COPY_OOM_KB, aData.DataLength());
     return NS_ERROR_OUT_OF_MEMORY;
   }
 
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 884ad69ca..88cebe42b 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -211,7 +211,6 @@
 #include "mozilla/AddonPathService.h"
 #include "mozilla/BasePrincipal.h"
 #include "mozilla/Services.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/dom/Location.h"
 #include "nsHTMLDocument.h"
 #include "nsWrapperCacheInlines.h"
@@ -1759,9 +1758,6 @@ nsGlobalWindow::~nsGlobalWindow()
 
     DropOuterWindowDocs();
   } else {
-    Telemetry::Accumulate(Telemetry::INNERWINDOWS_WITH_MUTATION_LISTENERS,
-                          mMutationBits ? 1 : 0);
-
     if (mListenerManager) {
       mListenerManager->Disconnect();
       mListenerManager = nullptr;
@@ -2695,7 +2691,6 @@ TreatAsRemoteXUL(nsIPrincipal* aPrincipal)
 static bool
 EnablePrivilege(JSContext* cx, unsigned argc, JS::Value* vp)
 {
-  Telemetry::Accumulate(Telemetry::ENABLE_PRIVILEGE_EVER_CALLED, true);
   return xpc::EnableUniversalXPConnect(cx);
 }
 
@@ -3389,9 +3384,6 @@ nsGlobalWindow::InnerSetNewDocument(JSContext* aCx, nsIDocument* aDocument)
   mLastOpenedURI = aDocument->GetDocumentURI();
 #endif
 
-  Telemetry::Accumulate(Telemetry::INNERWINDOWS_WITH_MUTATION_LISTENERS,
-                        mMutationBits ? 1 : 0);
-
   // Clear our mutation bitfield.
   mMutationBits = 0;
 }
@@ -6848,8 +6840,6 @@ FullscreenTransitionTask::Run()
       Preferences::GetUint("full-screen-api.transition.timeout", 1000);
     mTimer->Init(observer, timeout, nsITimer::TYPE_ONE_SHOT);
   } else if (stage == eAfterToggle) {
-    Telemetry::AccumulateTimeDelta(Telemetry::FULLSCREEN_TRANSITION_BLACK_MS,
-                                   mFullscreenChangeStartTime);
     mWidget->PerformFullscreenTransition(nsIWidget::eAfterFullscreenToggle,
                                          mDuration.mFadeOut, mTransitionData,
                                          this);
@@ -11577,11 +11567,6 @@ nsGlobalWindow::ShowSlowScriptDialog()
   unsigned lineno;
   bool hasFrame = JS::DescribeScriptedCaller(cx, &filename, &lineno);
 
-  // Record the slow script event if we haven't done so already for this inner window
-  // (which represents a particular page to the user).
-  if (!mHasHadSlowScript) {
-    Telemetry::Accumulate(Telemetry::SLOW_SCRIPT_PAGE_COUNT, 1);
-  }
   mHasHadSlowScript = true;
 
   if (XRE_IsContentProcess() &&
@@ -11613,10 +11598,6 @@ nsGlobalWindow::ShowSlowScriptDialog()
     return ContinueSlowScriptAndKeepNotifying;
   }
 
-  // Reached only on non-e10s - once per slow script dialog.
-  // On e10s - we probe once at ProcessHangsMonitor.jsm
-  Telemetry::Accumulate(Telemetry::SLOW_SCRIPT_NOTICE_COUNT, 1);
-
   // Get the nsIPrompt interface from the docshell
   nsCOMPtr<nsIDocShell> ds = GetDocShell();
   NS_ENSURE_TRUE(ds, KillSlowScript);
diff --git a/dom/base/nsJSEnvironment.cpp b/dom/base/nsJSEnvironment.cpp
index 3be1a6d2f..4a984d294 100644
--- a/dom/base/nsJSEnvironment.cpp
+++ b/dom/base/nsJSEnvironment.cpp
@@ -70,7 +70,6 @@
 #include "prthread.h"
 
 #include "mozilla/Preferences.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/asmjscache/AsmJSCache.h"
@@ -1477,22 +1476,8 @@ nsJSContext::EndCycleCollectionCallback(CycleCollectorResults &aResults)
            NS_GC_DELAY - std::min(ccNowDuration, kMaxICCDuration));
   }
 
-  // Log information about the CC via telemetry, JSON and the console.
-  Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_FINISH_IGC, gCCStats.mAnyLockedOut);
-  Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_SYNC_SKIPPABLE, gCCStats.mRanSyncForgetSkippable);
-  Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_FULL, ccNowDuration);
-  Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_MAX_PAUSE, gCCStats.mMaxSliceTime);
-
-  if (!sLastCCEndTime.IsNull()) {
-    // TimeBetween returns milliseconds, but we want to report seconds.
-    uint32_t timeBetween = TimeBetween(sLastCCEndTime, gCCStats.mBeginTime) / 1000;
-    Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_TIME_BETWEEN, timeBetween);
-  }
   sLastCCEndTime = endCCTimeStamp;
 
-  Telemetry::Accumulate(Telemetry::FORGET_SKIPPABLE_MAX,
-                        sMaxForgetSkippableTime / PR_USEC_PER_MSEC);
-
   PRTime delta = GetCollectionTimeDelta();
 
   uint32_t cleanups = sForgetSkippableBeforeCC ? sForgetSkippableBeforeCC : 1;
diff --git a/dom/base/nsNodeInfoManager.cpp b/dom/base/nsNodeInfoManager.cpp
index 66c8c84cf..80f0aa786 100644
--- a/dom/base/nsNodeInfoManager.cpp
+++ b/dom/base/nsNodeInfoManager.cpp
@@ -392,9 +392,6 @@ nsNodeInfoManager::SetDocumentPrincipal(nsIPrincipal *aPrincipal)
   NS_ASSERTION(aPrincipal, "Must have principal by this point!");
   MOZ_DIAGNOSTIC_ASSERT(!nsContentUtils::IsExpandedPrincipal(aPrincipal),
                         "Documents shouldn't have an expanded principal");
-  if (nsContentUtils::IsExpandedPrincipal(aPrincipal)) {
-    Telemetry::Accumulate(Telemetry::DOCUMENT_WITH_EXPANDED_PRINCIPAL, 1);
-  }
 
   mPrincipal = aPrincipal;
 }
diff --git a/dom/base/nsObjectLoadingContent.cpp b/dom/base/nsObjectLoadingContent.cpp
index 9e9dacf01..709c7aa56 100644
--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -85,7 +85,6 @@
 #include "mozilla/AsyncEventDispatcher.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/EventStates.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/dom/HTMLObjectElementBinding.h"
 #include "mozilla/dom/HTMLSharedObjectElement.h"
 #include "nsChannelClassifier.h"
@@ -1149,7 +1148,6 @@ nsObjectLoadingContent::OnStartRequest(nsIRequest *aRequest,
         NS_LITERAL_STRING(" since it was found on an internal Firefox blocklist.");
       console->LogStringMessage(message.get());
     }
-    Telemetry::Accumulate(Telemetry::PLUGIN_BLOCKED_FOR_STABILITY, 1);
     mContentBlockingEnabled = true;
     return NS_ERROR_FAILURE;
   } else if (status == NS_ERROR_TRACKING_URI) {
@@ -1565,7 +1563,6 @@ nsObjectLoadingContent::MaybeRewriteYoutubeEmbed(nsIURI* aURI, nsIURI* aBaseURI,
   }
 
   if (uri.Find("enablejsapi=1", true, 0, -1) != kNotFound) {
-    Telemetry::Accumulate(Telemetry::YOUTUBE_NONREWRITABLE_EMBED_SEEN, 1);
     return;
   }
 
@@ -1585,10 +1582,6 @@ nsObjectLoadingContent::MaybeRewriteYoutubeEmbed(nsIURI* aURI, nsIURI* aBaseURI,
     }
   }
 
-  // If we've made it this far, we've got a rewritable embed. Log it in
-  // telemetry.
-  Telemetry::Accumulate(Telemetry::YOUTUBE_REWRITABLE_EMBED_SEEN, 1);
-
   // If we're pref'd off, return after telemetry has been logged.
   if (!Preferences::GetBool(kPrefYoutubeRewrite)) {
     return;
@@ -3800,8 +3793,6 @@ nsObjectLoadingContent::LegacyCall(JSContext* aCx,
     aRv.Throw(NS_ERROR_FAILURE);
     return;
   }
-
-  Telemetry::Accumulate(Telemetry::PLUGIN_CALLED_DIRECTLY, true);
 }
 
 void
diff --git a/dom/bindings/BindingUtils.cpp b/dom/bindings/BindingUtils.cpp
index 7056658a7..323feca52 100644
--- a/dom/bindings/BindingUtils.cpp
+++ b/dom/bindings/BindingUtils.cpp
@@ -119,7 +119,7 @@ ThrowInvalidThis(JSContext* aCx, const JS::CallArgs& aArgs,
                              MSG_METHOD_THIS_DOES_NOT_IMPLEMENT_INTERFACE;
   MOZ_RELEASE_ASSERT(GetErrorArgCount(errorNumber) <= 2);
   JS_ReportErrorNumberUC(aCx, GetErrorMessage, nullptr,
-                         static_cast<const unsigned>(errorNumber),
+                         static_cast<unsigned>(errorNumber),
                          funcNameStr.get(), ifaceName.get());
   return false;
 }
@@ -226,7 +226,7 @@ TErrorResult<CleanupPolicy>::SetPendingExceptionWithMessage(JSContext* aCx)
   args[argCount] = nullptr;
 
   JS_ReportErrorNumberUCArray(aCx, dom::GetErrorMessage, nullptr,
-                              static_cast<const unsigned>(message->mErrorNumber),
+                              static_cast<unsigned>(message->mErrorNumber),
                               argCount > 0 ? args : nullptr);
 
   ClearMessage();
diff --git a/dom/bindings/BindingUtils.h b/dom/bindings/BindingUtils.h
index 3e58390c9..24b47a545 100644
--- a/dom/bindings/BindingUtils.h
+++ b/dom/bindings/BindingUtils.h
@@ -515,7 +515,7 @@ class ProtoAndIfaceCache
   {
   public:
     PageTableCache() {
-      memset(&mPages, 0, sizeof(mPages));
+      memset(mPages.begin(), 0, sizeof(mPages));
     }
 
     ~PageTableCache() {
diff --git a/dom/bindings/Bindings.conf b/dom/bindings/Bindings.conf
index aa7f26ad6..6f9733c5f 100644
--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -1222,6 +1222,11 @@ DOMInterfaces = {
     'headerFile': 'WebGLExtensions.h'
 },
 
+'MOZ_debug_get': {
+    'nativeType': 'mozilla::WebGLExtensionDebugGet',
+    'headerFile': 'WebGLExtensions.h'
+},
+
 'WebGLFramebuffer': {
     'nativeType': 'mozilla::WebGLFramebuffer',
     'headerFile': 'WebGLFramebuffer.h'
diff --git a/dom/bindings/ErrorResult.h b/dom/bindings/ErrorResult.h
index 7c3fc9e2f..da7ec30e7 100644
--- a/dom/bindings/ErrorResult.h
+++ b/dom/bindings/ErrorResult.h
@@ -75,7 +75,7 @@ template<typename... Ts>
 inline bool
 ThrowErrorMessage(JSContext* aCx, const ErrNum aErrorNumber, Ts&&... aArgs)
 {
-  binding_detail::ThrowErrorMessage(aCx, static_cast<const unsigned>(aErrorNumber),
+  binding_detail::ThrowErrorMessage(aCx, static_cast<unsigned>(aErrorNumber),
                                     mozilla::Forward<Ts>(aArgs)...);
   return false;
 }
diff --git a/dom/bindings/test/test_dom_xrays.html b/dom/bindings/test/test_dom_xrays.html
index 0700db2f8..15d7013ad 100644
--- a/dom/bindings/test/test_dom_xrays.html
+++ b/dom/bindings/test/test_dom_xrays.html
@@ -172,7 +172,7 @@ function test()
 
   // Check that DataTransfer's .types has the hack to alias contains()
   // to includes().
-  var dataTransfer = new win.DataTransfer("foo", true);
+  var dataTransfer = new win.DataTransfer();
   is(dataTransfer.types.contains, dataTransfer.types.includes,
      "Should have contains() set up as an alias to includes()");
   // Waive Xrays on the dataTransfer itself, since the .types we get is
diff --git a/dom/canvas/CanvasRenderingContextHelper.cpp b/dom/canvas/CanvasRenderingContextHelper.cpp
index 3000e59bd..61317fb51 100644
--- a/dom/canvas/CanvasRenderingContextHelper.cpp
+++ b/dom/canvas/CanvasRenderingContextHelper.cpp
@@ -7,7 +7,6 @@
 #include "ImageBitmapRenderingContext.h"
 #include "ImageEncoder.h"
 #include "mozilla/dom/CanvasRenderingContext2D.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/UniquePtr.h"
 #include "nsContentUtils.h"
 #include "nsDOMJSUtils.h"
@@ -138,13 +137,10 @@ CanvasRenderingContextHelper::CreateContextHelper(CanvasContextType aContextType
     break;
 
   case CanvasContextType::Canvas2D:
-    Telemetry::Accumulate(Telemetry::CANVAS_2D_USED, 1);
     ret = new CanvasRenderingContext2D(aCompositorBackend);
     break;
 
   case CanvasContextType::WebGL1:
-    Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_USED, 1);
-
     ret = WebGL1Context::Create();
     if (!ret)
       return nullptr;
@@ -152,8 +148,6 @@ CanvasRenderingContextHelper::CreateContextHelper(CanvasContextType aContextType
     break;
 
   case CanvasContextType::WebGL2:
-    Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_USED, 1);
-
     ret = WebGL2Context::Create();
     if (!ret)
       return nullptr;
@@ -205,16 +199,8 @@ CanvasRenderingContextHelper::GetContext(JSContext* aCx,
       // See bug 645792 and bug 1215072.
       // We want to throw only if dictionary initialization fails,
       // so only in case aRv has been set to some error value.
-      if (contextType == CanvasContextType::WebGL1)
-        Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_SUCCESS, 0);
-      else if (contextType == CanvasContextType::WebGL2)
-        Telemetry::Accumulate(Telemetry::CANVAS_WEBGL2_SUCCESS, 0);
       return nullptr;
     }
-    if (contextType == CanvasContextType::WebGL1)
-      Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_SUCCESS, 1);
-    else if (contextType == CanvasContextType::WebGL2)
-      Telemetry::Accumulate(Telemetry::CANVAS_WEBGL2_SUCCESS, 1);
   } else {
     // We already have a context of some type.
     if (contextType != mCurrentContextType)
diff --git a/dom/canvas/WebGL1Context.cpp b/dom/canvas/WebGL1Context.cpp
index c1818a3f9..e82cafbe5 100644
--- a/dom/canvas/WebGL1Context.cpp
+++ b/dom/canvas/WebGL1Context.cpp
@@ -6,7 +6,6 @@
 #include "WebGL1Context.h"
 
 #include "mozilla/dom/WebGLRenderingContextBinding.h"
-#include "mozilla/Telemetry.h"
 #include "WebGLFormats.h"
 
 namespace mozilla {
@@ -43,8 +42,6 @@ WebGL1Context::WrapObject(JSContext* cx, JS::Handle<JSObject*> givenProto)
 nsresult
 NS_NewCanvasRenderingContextWebGL(nsIDOMWebGLRenderingContext** out_result)
 {
-    mozilla::Telemetry::Accumulate(mozilla::Telemetry::CANVAS_WEBGL_USED, 1);
-
     nsIDOMWebGLRenderingContext* ctx = mozilla::WebGL1Context::Create();
 
     NS_ADDREF(*out_result = ctx);
diff --git a/dom/canvas/WebGLContext.cpp b/dom/canvas/WebGLContext.cpp
index 32eed6354..14bc7e3e3 100644
--- a/dom/canvas/WebGLContext.cpp
+++ b/dom/canvas/WebGLContext.cpp
@@ -825,10 +825,6 @@ NS_IMETHODIMP
 WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
 {
     if (signedWidth < 0 || signedHeight < 0) {
-        if (!gl) {
-            Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_FAILURE_ID,
-                                  NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_SIZE"));
-        }
         GenerateWarning("Canvas size is too large (seems like a negative value wrapped)");
         return NS_ERROR_OUT_OF_MEMORY;
     }
@@ -884,12 +880,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
         return NS_OK;
     }
 
-    nsCString failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_UNKOWN");
-    auto autoTelemetry = mozilla::MakeScopeExit([&] {
-        Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_FAILURE_ID,
-                              failureId);
-    });
-
     // End of early return cases.
     // At this point we know that we're not just resizing an existing context,
     // we are initializing a new context.
@@ -911,7 +901,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
     // resource handles created from older context generations.
     if (!(mGeneration + 1).isValid()) {
         // exit without changing the value of mGeneration
-        failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_TOO_MANY");
         const nsLiteralCString text("Too many WebGL contexts created this run.");
         ThrowEvent_WebGLContextCreationError(text);
         return NS_ERROR_FAILURE;
@@ -928,11 +917,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
     disabled |= gfxPlatform::InSafeMode();
 
     if (disabled) {
-        if (gfxPlatform::InSafeMode()) {
-            failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_SAFEMODE");
-        } else {
-            failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_DISABLED");
-        }
         const nsLiteralCString text("WebGL is currently disabled.");
         ThrowEvent_WebGLContextCreationError(text);
         return NS_ERROR_FAILURE;
@@ -945,7 +929,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
     if (mOptions.failIfMajorPerformanceCaveat) {
         nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
         if (!HasAcceleratedLayers(gfxInfo)) {
-            failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_PERF_CAVEAT");
             const nsLiteralCString text("failIfMajorPerformanceCaveat: Compositor is not"
                                         " hardware-accelerated.");
             ThrowEvent_WebGLContextCreationError(text);
@@ -961,12 +944,9 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
     if (!CreateAndInitGL(forceEnabled, &failReasons)) {
         nsCString text("WebGL creation failed: ");
         for (const auto& cur : failReasons) {
-            Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_FAILURE_ID, cur.key);
-
             text.AppendASCII("\n* ");
             text.Append(cur.info);
         }
-        failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_REASON");
         ThrowEvent_WebGLContextCreationError(text);
         return NS_ERROR_FAILURE;
     }
@@ -978,7 +958,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
             DestroyResourcesAndContext();
             MOZ_ASSERT(!gl);
 
-            failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_PERF_WARP");
             const nsLiteralCString text("failIfMajorPerformanceCaveat: Driver is not"
                                         " hardware-accelerated.");
             ThrowEvent_WebGLContextCreationError(text);
@@ -992,7 +971,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
             DestroyResourcesAndContext();
             MOZ_ASSERT(!gl);
 
-            failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_DXGL_INTEROP2");
             const nsLiteralCString text("Caveat: WGL without DXGLInterop2.");
             ThrowEvent_WebGLContextCreationError(text);
             return NS_ERROR_FAILURE;
@@ -1001,7 +979,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
     }
 
     if (!ResizeBackbuffer(width, height)) {
-        failureId = NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_BACKBUFFER");
         const nsLiteralCString text("Initializing WebGL backbuffer failed.");
         ThrowEvent_WebGLContextCreationError(text);
         return NS_ERROR_FAILURE;
@@ -1085,7 +1062,6 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
 
     //////
 
-    failureId = NS_LITERAL_CSTRING("SUCCESS");
     return NS_OK;
 }
 
diff --git a/dom/canvas/WebGLContextExtensions.cpp b/dom/canvas/WebGLContextExtensions.cpp
index 4a5a23274..7f338b4e9 100644
--- a/dom/canvas/WebGLContextExtensions.cpp
+++ b/dom/canvas/WebGLContextExtensions.cpp
@@ -40,6 +40,7 @@ WebGLContext::GetExtensionString(WebGLExtensionID ext)
         WEBGL_EXTENSION_IDENTIFIER(EXT_sRGB)
         WEBGL_EXTENSION_IDENTIFIER(EXT_texture_filter_anisotropic)
         WEBGL_EXTENSION_IDENTIFIER(EXT_disjoint_timer_query)
+        WEBGL_EXTENSION_IDENTIFIER(MOZ_debug_get)
         WEBGL_EXTENSION_IDENTIFIER(OES_element_index_uint)
         WEBGL_EXTENSION_IDENTIFIER(OES_standard_derivatives)
         WEBGL_EXTENSION_IDENTIFIER(OES_texture_float)
@@ -91,6 +92,8 @@ bool WebGLContext::IsExtensionSupported(dom::CallerType callerType,
         switch (ext) {
         case WebGLExtensionID::EXT_disjoint_timer_query:
             return WebGLExtensionDisjointTimerQuery::IsSupported(this);
+        case WebGLExtensionID::MOZ_debug_get:
+            return true;
         case WebGLExtensionID::WEBGL_debug_renderer_info:
             return true;
         case WebGLExtensionID::WEBGL_debug_shaders:
@@ -372,6 +375,11 @@ WebGLContext::EnableExtension(WebGLExtensionID ext)
         obj = new WebGLExtensionTextureFilterAnisotropic(this);
         break;
 
+    // MOZ_
+    case WebGLExtensionID::MOZ_debug_get:
+        obj = new WebGLExtensionDebugGet(this);
+        break;
+
     // OES_
     case WebGLExtensionID::OES_element_index_uint:
         obj = new WebGLExtensionElementIndexUint(this);
diff --git a/dom/canvas/WebGLContextState.cpp b/dom/canvas/WebGLContextState.cpp
index e0234f5c6..c2f4c1a75 100644
--- a/dom/canvas/WebGLContextState.cpp
+++ b/dom/canvas/WebGLContextState.cpp
@@ -61,18 +61,6 @@ WebGLContext::Enable(GLenum cap)
     gl->fEnable(cap);
 }
 
-static JS::Value
-StringValue(JSContext* cx, const nsAString& str, ErrorResult& rv)
-{
-    JSString* jsStr = JS_NewUCStringCopyN(cx, str.BeginReading(), str.Length());
-    if (!jsStr) {
-        rv.Throw(NS_ERROR_OUT_OF_MEMORY);
-        return JS::NullValue();
-    }
-
-    return JS::StringValue(jsStr);
-}
-
 bool
 WebGLContext::GetStencilBits(GLint* const out_stencilBits)
 {
diff --git a/dom/canvas/WebGLContextUtils.cpp b/dom/canvas/WebGLContextUtils.cpp
index 9c0d34939..3fd32eb30 100644
--- a/dom/canvas/WebGLContextUtils.cpp
+++ b/dom/canvas/WebGLContextUtils.cpp
@@ -874,4 +874,16 @@ InfoFrom(WebGLTexImageFunc func, WebGLTexDimensions dims)
     }
 }
 
+JS::Value
+StringValue(JSContext* cx, const nsAString& str, ErrorResult& er)
+{
+    JSString* jsStr = JS_NewUCStringCopyN(cx, str.BeginReading(), str.Length());
+    if (!jsStr) {
+        er.Throw(NS_ERROR_OUT_OF_MEMORY);
+        return JS::NullValue();
+    }
+
+    return JS::StringValue(jsStr);
+}
+
 } // namespace mozilla
diff --git a/dom/canvas/WebGLContextUtils.h b/dom/canvas/WebGLContextUtils.h
index 5401fc878..1d06659b1 100644
--- a/dom/canvas/WebGLContextUtils.h
+++ b/dom/canvas/WebGLContextUtils.h
@@ -94,6 +94,8 @@ WebGLContext::WebGLObjectAsJSObject(JSContext* cx,
  */
 const char* InfoFrom(WebGLTexImageFunc func, WebGLTexDimensions dims);
 
+JS::Value StringValue(JSContext* cx, const nsAString& str, ErrorResult& er);
+
 } // namespace mozilla
 
 #endif // WEBGL_CONTEXT_UTILS_H_
diff --git a/dom/canvas/WebGLExtensionDebugGet.cpp b/dom/canvas/WebGLExtensionDebugGet.cpp
new file mode 100644
index 000000000..39bb3c57a
--- /dev/null
+++ b/dom/canvas/WebGLExtensionDebugGet.cpp
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "WebGLExtensions.h"
+
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+#include "WebGLContext.h"
+#include "WebGLContextUtils.h"
+
+namespace mozilla {
+
+WebGLExtensionDebugGet::WebGLExtensionDebugGet(WebGLContext* webgl)
+    : WebGLExtensionBase(webgl)
+{
+}
+
+WebGLExtensionDebugGet::~WebGLExtensionDebugGet()
+{
+}
+
+void
+WebGLExtensionDebugGet::GetParameter(JSContext* cx, GLenum pname,
+                                     JS::MutableHandle<JS::Value> retval,
+                                     ErrorResult& er) const
+{
+    const auto& gl = mContext->gl;
+    gl->MakeCurrent();
+
+    switch (pname) {
+    case LOCAL_GL_EXTENSIONS:
+        {
+            nsString ret;
+            if (!gl->IsCoreProfile()) {
+                const auto rawExts = (const char*)gl->fGetString(LOCAL_GL_EXTENSIONS);
+                ret = NS_ConvertUTF8toUTF16(rawExts);
+            } else {
+                const auto& numExts = gl->GetIntAs<GLuint>(LOCAL_GL_NUM_EXTENSIONS);
+                for (GLuint i = 0; i < numExts; i++) {
+                    const auto rawExt = (const char*)gl->fGetStringi(LOCAL_GL_EXTENSIONS,
+                                                                     i);
+                    if (i > 0) {
+                        ret.AppendLiteral(" ");
+                    }
+                    ret.Append(NS_ConvertUTF8toUTF16(rawExt));
+                }
+            }
+            retval.set(StringValue(cx, ret, er));
+            return;
+        }
+
+    case LOCAL_GL_RENDERER:
+    case LOCAL_GL_VENDOR:
+    case LOCAL_GL_VERSION:
+        {
+            const auto raw = (const char*)gl->fGetString(pname);
+            retval.set(StringValue(cx, NS_ConvertUTF8toUTF16(raw), er));
+            return;
+        }
+
+    case 0x10000: // "WSI_INFO"
+        {
+            nsCString info;
+            gl->GetWSIInfo(&info);
+            retval.set(StringValue(cx, NS_ConvertUTF8toUTF16(info), er));
+            return;
+        }
+
+    default:
+        mContext->ErrorInvalidEnumArg("MOZ_debug_get.getParameter", "pname", pname);
+        retval.set(JS::NullValue());
+        return;
+    }
+}
+
+IMPL_WEBGL_EXTENSION_GOOP(WebGLExtensionDebugGet, MOZ_debug_get)
+
+} // namespace mozilla
diff --git a/dom/canvas/WebGLExtensions.h b/dom/canvas/WebGLExtensions.h
index 741f6997f..7b6b6b54b 100644
--- a/dom/canvas/WebGLExtensions.h
+++ b/dom/canvas/WebGLExtensions.h
@@ -12,6 +12,7 @@
 #include "WebGLTypes.h"
 
 namespace mozilla {
+class ErrorResult;
 
 namespace dom {
 template<typename T>
@@ -385,6 +386,19 @@ public:
     DECL_WEBGL_EXTENSION_GOOP
 };
 
+class WebGLExtensionDebugGet final
+    : public WebGLExtensionBase
+{
+public:
+    explicit WebGLExtensionDebugGet(WebGLContext* webgl);
+    virtual ~WebGLExtensionDebugGet();
+
+    void GetParameter(JSContext* cx, GLenum pname,
+                      JS::MutableHandle<JS::Value> retval, ErrorResult& er) const;
+
+    DECL_WEBGL_EXTENSION_GOOP
+};
+
 } // namespace mozilla
 
 #endif // WEBGL_EXTENSIONS_H_
diff --git a/dom/canvas/WebGLTypes.h b/dom/canvas/WebGLTypes.h
index 42b8701f3..2f4a4368a 100644
--- a/dom/canvas/WebGLTypes.h
+++ b/dom/canvas/WebGLTypes.h
@@ -149,6 +149,7 @@ enum class WebGLExtensionID : uint8_t {
     EXT_shader_texture_lod,
     EXT_texture_filter_anisotropic,
     EXT_disjoint_timer_query,
+    MOZ_debug_get,
     OES_element_index_uint,
     OES_standard_derivatives,
     OES_texture_float,
diff --git a/dom/canvas/moz.build b/dom/canvas/moz.build
index f7555b33d..6d5e2756f 100644
--- a/dom/canvas/moz.build
+++ b/dom/canvas/moz.build
@@ -105,6 +105,7 @@ UNIFIED_SOURCES += [
     'WebGLExtensionCompressedTextureETC1.cpp',
     'WebGLExtensionCompressedTexturePVRTC.cpp',
     'WebGLExtensionCompressedTextureS3TC.cpp',
+    'WebGLExtensionDebugGet.cpp',
     'WebGLExtensionDebugRendererInfo.cpp',
     'WebGLExtensionDebugShaders.cpp',
     'WebGLExtensionDepthTexture.cpp',
diff --git a/dom/crypto/WebCryptoTask.cpp b/dom/crypto/WebCryptoTask.cpp
index f5fc7b5bc..c4cc7080d 100644
--- a/dom/crypto/WebCryptoTask.cpp
+++ b/dom/crypto/WebCryptoTask.cpp
@@ -452,7 +452,6 @@ void
 WebCryptoTask::FailWithError(nsresult aRv)
 {
   MOZ_ASSERT(IsOnOriginalThread());
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_RESOLVED, false);
 
   // Blindly convert nsresult to DOMException
   // Individual tasks must ensure they pass the right values
@@ -491,7 +490,6 @@ WebCryptoTask::CallCallback(nsresult rv)
   }
 
   Resolve();
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_RESOLVED, true);
 
   // Manually release mResultPromise while we're on the main thread
   mResultPromise = nullptr;
@@ -650,7 +648,6 @@ public:
       mEarlyRv = NS_ERROR_DOM_NOT_SUPPORTED_ERR;
       return;
     }
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, telemetryAlg);
   }
 
 private:
@@ -794,7 +791,6 @@ public:
       return;
     }
 
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_AES_KW);
   }
 
 private:
@@ -908,8 +904,6 @@ public:
   void Init(JSContext* aCx, const ObjectOrString& aAlgorithm,
             CryptoKey& aKey, bool aEncrypt)
   {
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_RSA_OAEP);
-
     CHECK_KEY_ALGORITHM(aKey.Algorithm(), WEBCRYPTO_ALG_RSA_OAEP);
 
     if (mEncrypt) {
@@ -1049,7 +1043,6 @@ public:
       case CKM_SHA512_HMAC: telemetryAlg = TA_HMAC_SHA_512; break;
       default:              telemetryAlg = TA_UNKNOWN;
     }
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, telemetryAlg);
   }
 
 private:
@@ -1158,12 +1151,10 @@ public:
 
     if (algName.EqualsLiteral(WEBCRYPTO_ALG_RSASSA_PKCS1)) {
       mAlgorithm = Algorithm::RSA_PKCS1;
-      Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_RSASSA_PKCS1);
       CHECK_KEY_ALGORITHM(aKey.Algorithm(), WEBCRYPTO_ALG_RSASSA_PKCS1);
       hashAlgName = aKey.Algorithm().mRsa.mHash.mName;
     } else if (algName.EqualsLiteral(WEBCRYPTO_ALG_RSA_PSS)) {
       mAlgorithm = Algorithm::RSA_PSS;
-      Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_RSA_PSS);
       CHECK_KEY_ALGORITHM(aKey.Algorithm(), WEBCRYPTO_ALG_RSA_PSS);
 
       KeyAlgorithm& hashAlg = aKey.Algorithm().mRsa.mHash;
@@ -1188,7 +1179,6 @@ public:
       mSaltLength = params.mSaltLength;
     } else if (algName.EqualsLiteral(WEBCRYPTO_ALG_ECDSA)) {
       mAlgorithm = Algorithm::ECDSA;
-      Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_ECDSA);
       CHECK_KEY_ALGORITHM(aKey.Algorithm(), WEBCRYPTO_ALG_ECDSA);
 
       // For ECDSA, the hash name comes from the algorithm parameter
@@ -1356,7 +1346,6 @@ public:
       mEarlyRv = NS_ERROR_DOM_SYNTAX_ERR;
       return;
     }
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, telemetryAlg);
     mOidTag = MapHashAlgorithmNameToOID(algName);
   }
 
@@ -2656,7 +2645,6 @@ public:
   void Init(JSContext* aCx, const ObjectOrString& aAlgorithm, CryptoKey& aKey,
             uint32_t aLength)
   {
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_HKDF);
     CHECK_KEY_ALGORITHM(aKey.Algorithm(), WEBCRYPTO_ALG_HKDF);
 
     // Check that we have a key.
@@ -2806,7 +2794,6 @@ public:
   void Init(JSContext* aCx, const ObjectOrString& aAlgorithm, CryptoKey& aKey,
             uint32_t aLength)
   {
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_PBKDF2);
     CHECK_KEY_ALGORITHM(aKey.Algorithm(), WEBCRYPTO_ALG_PBKDF2);
 
     // Check that we got a symmetric key
@@ -2981,7 +2968,6 @@ public:
 
   void Init(JSContext* aCx, const ObjectOrString& aAlgorithm, CryptoKey& aKey)
   {
-    Telemetry::Accumulate(Telemetry::WEBCRYPTO_ALG, TA_ECDH);
     CHECK_KEY_ALGORITHM(aKey.Algorithm(), WEBCRYPTO_ALG_ECDH);
 
     // Check that we have a private key.
@@ -3277,10 +3263,6 @@ WebCryptoTask::CreateEncryptDecryptTask(JSContext* aCx,
                                         const CryptoOperationData& aData,
                                         bool aEncrypt)
 {
-  TelemetryMethod method = (aEncrypt)? TM_ENCRYPT : TM_DECRYPT;
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, method);
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_EXTRACTABLE_ENC, aKey.Extractable());
-
   // Ensure key is usable for this operation
   if ((aEncrypt  && !aKey.HasUsage(CryptoKey::ENCRYPT)) ||
       (!aEncrypt && !aKey.HasUsage(CryptoKey::DECRYPT))) {
@@ -3312,10 +3294,6 @@ WebCryptoTask::CreateSignVerifyTask(JSContext* aCx,
                                     const CryptoOperationData& aData,
                                     bool aSign)
 {
-  TelemetryMethod method = (aSign)? TM_SIGN : TM_VERIFY;
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, method);
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_EXTRACTABLE_SIG, aKey.Extractable());
-
   // Ensure key is usable for this operation
   if ((aSign  && !aKey.HasUsage(CryptoKey::SIGN)) ||
       (!aSign && !aKey.HasUsage(CryptoKey::VERIFY))) {
@@ -3345,8 +3323,6 @@ WebCryptoTask::CreateDigestTask(JSContext* aCx,
                                 const ObjectOrString& aAlgorithm,
                                 const CryptoOperationData& aData)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_DIGEST);
-
   nsString algName;
   nsresult rv = GetAlgorithmName(aCx, aAlgorithm, algName);
   if (NS_FAILED(rv)) {
@@ -3372,9 +3348,6 @@ WebCryptoTask::CreateImportKeyTask(nsIGlobalObject* aGlobal,
                                    bool aExtractable,
                                    const Sequence<nsString>& aKeyUsages)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_IMPORTKEY);
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_EXTRACTABLE_IMPORT, aExtractable);
-
   // Verify that the format is recognized
   if (!aFormat.EqualsLiteral(WEBCRYPTO_KEY_FORMAT_RAW) &&
       !aFormat.EqualsLiteral(WEBCRYPTO_KEY_FORMAT_SPKI) &&
@@ -3426,8 +3399,6 @@ WebCryptoTask*
 WebCryptoTask::CreateExportKeyTask(const nsAString& aFormat,
                                    CryptoKey& aKey)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_EXPORTKEY);
-
   // Verify that the format is recognized
   if (!aFormat.EqualsLiteral(WEBCRYPTO_KEY_FORMAT_RAW) &&
       !aFormat.EqualsLiteral(WEBCRYPTO_KEY_FORMAT_SPKI) &&
@@ -3470,9 +3441,6 @@ WebCryptoTask::CreateGenerateKeyTask(nsIGlobalObject* aGlobal,
                                      bool aExtractable,
                                      const Sequence<nsString>& aKeyUsages)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_GENERATEKEY);
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_EXTRACTABLE_GENERATE, aExtractable);
-
   // Verify that aKeyUsages does not contain an unrecognized value
   // SPEC-BUG: Spec says that this should be InvalidAccessError, but that
   // is inconsistent with other analogous points in the spec
@@ -3515,8 +3483,6 @@ WebCryptoTask::CreateDeriveKeyTask(nsIGlobalObject* aGlobal,
                                    bool aExtractable,
                                    const Sequence<nsString>& aKeyUsages)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_DERIVEKEY);
-
   // Ensure baseKey is usable for this operation
   if (!aBaseKey.HasUsage(CryptoKey::DERIVEKEY)) {
     return new FailureTask(NS_ERROR_DOM_INVALID_ACCESS_ERR);
@@ -3560,8 +3526,6 @@ WebCryptoTask::CreateDeriveBitsTask(JSContext* aCx,
                                     CryptoKey& aKey,
                                     uint32_t aLength)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_DERIVEBITS);
-
   // Ensure baseKey is usable for this operation
   if (!aKey.HasUsage(CryptoKey::DERIVEBITS)) {
     return new FailureTask(NS_ERROR_DOM_INVALID_ACCESS_ERR);
@@ -3599,8 +3563,6 @@ WebCryptoTask::CreateWrapKeyTask(JSContext* aCx,
                                  CryptoKey& aWrappingKey,
                                  const ObjectOrString& aWrapAlgorithm)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_WRAPKEY);
-
   // Verify that the format is recognized
   if (!aFormat.EqualsLiteral(WEBCRYPTO_KEY_FORMAT_RAW) &&
       !aFormat.EqualsLiteral(WEBCRYPTO_KEY_FORMAT_SPKI) &&
@@ -3652,8 +3614,6 @@ WebCryptoTask::CreateUnwrapKeyTask(nsIGlobalObject* aGlobal,
                                    bool aExtractable,
                                    const Sequence<nsString>& aKeyUsages)
 {
-  Telemetry::Accumulate(Telemetry::WEBCRYPTO_METHOD, TM_UNWRAPKEY);
-
   // Ensure key is usable for this operation
   if (!aUnwrappingKey.HasUsage(CryptoKey::UNWRAPKEY)) {
     return new FailureTask(NS_ERROR_DOM_INVALID_ACCESS_ERR);
diff --git a/dom/events/DataTransfer.cpp b/dom/events/DataTransfer.cpp
index 2c6ecdd56..45c72e662 100644
--- a/dom/events/DataTransfer.cpp
+++ b/dom/events/DataTransfer.cpp
@@ -161,22 +161,11 @@ DataTransfer::~DataTransfer()
 
 // static
 already_AddRefed<DataTransfer>
-DataTransfer::Constructor(const GlobalObject& aGlobal,
-                          const nsAString& aEventType, bool aIsExternal,
-                          ErrorResult& aRv)
+DataTransfer::Constructor(const GlobalObject& aGlobal, ErrorResult& aRv)
 {
-  nsAutoCString onEventType("on");
-  AppendUTF16toUTF8(aEventType, onEventType);
-  nsCOMPtr<nsIAtom> eventTypeAtom = NS_Atomize(onEventType);
-  if (!eventTypeAtom) {
-    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
-    return nullptr;
-  }
-
-  EventMessage eventMessage = nsContentUtils::GetEventMessage(eventTypeAtom);
   RefPtr<DataTransfer> transfer = new DataTransfer(aGlobal.GetAsSupports(),
-                                                     eventMessage, aIsExternal,
-                                                     -1);
+                                                   eCopy, /* is external */ false, /* clipboard type */ -1);
+  transfer->mEffectAllowed = nsIDragService::DRAGDROP_ACTION_NONE;
   return transfer.forget();
 }
 
diff --git a/dom/events/DataTransfer.h b/dom/events/DataTransfer.h
index 7c6b0b8c1..344593ed0 100644
--- a/dom/events/DataTransfer.h
+++ b/dom/events/DataTransfer.h
@@ -115,8 +115,7 @@ public:
   }
 
   static already_AddRefed<DataTransfer>
-  Constructor(const GlobalObject& aGlobal, const nsAString& aEventType,
-              bool aIsExternal, ErrorResult& aRv);
+  Constructor(const GlobalObject& aGlobal, ErrorResult& aRv);
 
   void GetDropEffect(nsString& aDropEffect)
   {
diff --git a/dom/events/EventDispatcher.cpp b/dom/events/EventDispatcher.cpp
index 65f01844b..1d4dfd7d9 100644
--- a/dom/events/EventDispatcher.cpp
+++ b/dom/events/EventDispatcher.cpp
@@ -858,63 +858,46 @@ EventDispatcher::CreateEvent(EventTarget* aOwner,
 
   // And if we didn't get an event, check the type argument.
 
-#define LOG_EVENT_CREATION(name) mozilla::Telemetry::Accumulate( \
-    mozilla::Telemetry::CREATE_EVENT_##name, true);
-
   if (aEventType.LowerCaseEqualsLiteral("mouseevent")) {
-    LOG_EVENT_CREATION(MOUSEEVENT);
     return NS_NewDOMMouseEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("mouseevents")) {
-    LOG_EVENT_CREATION(MOUSEEVENTS);
     return NS_NewDOMMouseEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("popupevents")) {
-    LOG_EVENT_CREATION(POPUPEVENTS);
     return NS_NewDOMMouseEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("mousescrollevents")) {
-    LOG_EVENT_CREATION(MOUSESCROLLEVENTS);
     return NS_NewDOMMouseScrollEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("dragevent")) {
-    LOG_EVENT_CREATION(DRAGEVENT);
     return NS_NewDOMDragEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("dragevents")) {
-    LOG_EVENT_CREATION(DRAGEVENTS);
     return NS_NewDOMDragEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("keyboardevent")) {
-    LOG_EVENT_CREATION(KEYBOARDEVENT);
     return NS_NewDOMKeyboardEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("keyevents")) {
-    LOG_EVENT_CREATION(KEYEVENTS);
     return NS_NewDOMKeyboardEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("compositionevent")) {
-    LOG_EVENT_CREATION(COMPOSITIONEVENT);
     return NS_NewDOMCompositionEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("textevent")) {
-    LOG_EVENT_CREATION(TEXTEVENT);
     return NS_NewDOMCompositionEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("textevents")) {
-    LOG_EVENT_CREATION(TEXTEVENTS);
     return NS_NewDOMCompositionEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("mutationevent")) {
-    LOG_EVENT_CREATION(MUTATIONEVENT);
     return NS_NewDOMMutationEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("mutationevents")) {
-    LOG_EVENT_CREATION(MUTATIONEVENTS);
     return NS_NewDOMMutationEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("deviceorientationevent")) {
-    LOG_EVENT_CREATION(DEVICEORIENTATIONEVENT);
     DeviceOrientationEventInit init;
     RefPtr<Event> event =
       DeviceOrientationEvent::Constructor(aOwner, EmptyString(), init);
@@ -922,97 +905,74 @@ EventDispatcher::CreateEvent(EventTarget* aOwner,
     return event.forget();
   }
   if (aEventType.LowerCaseEqualsLiteral("devicemotionevent")) {
-    LOG_EVENT_CREATION(DEVICEMOTIONEVENT);
     return NS_NewDOMDeviceMotionEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("uievent")) {
-    LOG_EVENT_CREATION(UIEVENT);
     return NS_NewDOMUIEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("uievents")) {
-    LOG_EVENT_CREATION(UIEVENTS);
     return NS_NewDOMUIEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("event")) {
-    LOG_EVENT_CREATION(EVENT);
     return NS_NewDOMEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("events")) {
-    LOG_EVENT_CREATION(EVENTS);
     return NS_NewDOMEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("htmlevents")) {
-    LOG_EVENT_CREATION(HTMLEVENTS);
     return NS_NewDOMEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("svgevent")) {
-    LOG_EVENT_CREATION(SVGEVENT);
     return NS_NewDOMEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("svgevents")) {
-    LOG_EVENT_CREATION(SVGEVENTS);
     return NS_NewDOMEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("svgzoomevent")) {
-    LOG_EVENT_CREATION(SVGZOOMEVENT);
     return NS_NewDOMSVGZoomEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("svgzoomevents")) {
-    LOG_EVENT_CREATION(SVGZOOMEVENTS);
     return NS_NewDOMSVGZoomEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("timeevent")) {
-    LOG_EVENT_CREATION(TIMEEVENT);
     return NS_NewDOMTimeEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("timeevents")) {
-    LOG_EVENT_CREATION(TIMEEVENTS);
     return NS_NewDOMTimeEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("xulcommandevent")) {
-    LOG_EVENT_CREATION(XULCOMMANDEVENT);
     return NS_NewDOMXULCommandEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("xulcommandevents")) {
-    LOG_EVENT_CREATION(XULCOMMANDEVENTS);
     return NS_NewDOMXULCommandEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("commandevent")) {
-    LOG_EVENT_CREATION(COMMANDEVENT);
     return NS_NewDOMCommandEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("commandevents")) {
-    LOG_EVENT_CREATION(COMMANDEVENTS);
     return NS_NewDOMCommandEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("datacontainerevent")) {
-    LOG_EVENT_CREATION(DATACONTAINEREVENT);
     return NS_NewDOMDataContainerEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("datacontainerevents")) {
-    LOG_EVENT_CREATION(DATACONTAINEREVENTS);
     return NS_NewDOMDataContainerEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("messageevent")) {
-    LOG_EVENT_CREATION(MESSAGEEVENT);
     RefPtr<Event> event = new MessageEvent(aOwner, aPresContext, nullptr);
     return event.forget();
   }
   if (aEventType.LowerCaseEqualsLiteral("notifypaintevent")) {
-    LOG_EVENT_CREATION(NOTIFYPAINTEVENT);
     return NS_NewDOMNotifyPaintEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("simplegestureevent")) {
-    LOG_EVENT_CREATION(SIMPLEGESTUREEVENT);
     return NS_NewDOMSimpleGestureEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("beforeunloadevent")) {
-    LOG_EVENT_CREATION(BEFOREUNLOADEVENT);
     return NS_NewDOMBeforeUnloadEvent(aOwner, aPresContext, nullptr);
   }
   // XXXkhuey this is broken
   if (aEventType.LowerCaseEqualsLiteral("pagetransition")) {
-    LOG_EVENT_CREATION(PAGETRANSITION);
     PageTransitionEventInit init;
     RefPtr<Event> event =
       PageTransitionEvent::Constructor(aOwner, EmptyString(), init);
@@ -1020,14 +980,12 @@ EventDispatcher::CreateEvent(EventTarget* aOwner,
     return event.forget();
   }
   if (aEventType.LowerCaseEqualsLiteral("scrollareaevent")) {
-    LOG_EVENT_CREATION(SCROLLAREAEVENT);
     return NS_NewDOMScrollAreaEvent(aOwner, aPresContext, nullptr);
   }
   // XXXkhuey Chrome supports popstateevent here, even though it provides no
   // initPopStateEvent method.  This is nuts ... but copying it is unlikely to
   // break the web.
   if (aEventType.LowerCaseEqualsLiteral("popstateevent")) {
-    LOG_EVENT_CREATION(POPSTATEEVENT);
     AutoJSContext cx;
     RootedDictionary<PopStateEventInit> init(cx);
     RefPtr<Event> event =
@@ -1037,11 +995,9 @@ EventDispatcher::CreateEvent(EventTarget* aOwner,
   }
   if (aEventType.LowerCaseEqualsLiteral("touchevent") &&
       TouchEvent::PrefEnabled(nsContentUtils::GetDocShellForEventTarget(aOwner))) {
-    LOG_EVENT_CREATION(TOUCHEVENT);
     return NS_NewDOMTouchEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("hashchangeevent")) {
-    LOG_EVENT_CREATION(HASHCHANGEEVENT);
     HashChangeEventInit init;
     RefPtr<Event> event =
       HashChangeEvent::Constructor(aOwner, EmptyString(), init);
@@ -1049,11 +1005,9 @@ EventDispatcher::CreateEvent(EventTarget* aOwner,
     return event.forget();
   }
   if (aEventType.LowerCaseEqualsLiteral("customevent")) {
-    LOG_EVENT_CREATION(CUSTOMEVENT);
     return NS_NewDOMCustomEvent(aOwner, aPresContext, nullptr);
   }
   if (aEventType.LowerCaseEqualsLiteral("storageevent")) {
-    LOG_EVENT_CREATION(STORAGEEVENT);
     return NS_NewDOMStorageEvent(aOwner);
   }
   if (aEventType.LowerCaseEqualsLiteral("focusevent")) {
@@ -1062,8 +1016,6 @@ EventDispatcher::CreateEvent(EventTarget* aOwner,
     return event.forget();
   }
 
-#undef LOG_EVENT_CREATION
-
   // NEW EVENT TYPES SHOULD NOT BE ADDED HERE; THEY SHOULD USE ONLY EVENT
   // CONSTRUCTORS
 
diff --git a/dom/events/EventStateManager.cpp b/dom/events/EventStateManager.cpp
index 7bbfe21b7..e16d68c81 100644
--- a/dom/events/EventStateManager.cpp
+++ b/dom/events/EventStateManager.cpp
@@ -3240,6 +3240,12 @@ EventStateManager::PostHandleEvent(nsPresContext* aPresContext,
         action = WheelPrefs::GetInstance()->ComputeActionFor(wheelEvent);
       }
       switch (action) {
+        case WheelPrefs::ACTION_HSCROLL: {
+          // Swap axes and fall through
+          double deltaX = wheelEvent->mDeltaX;
+          wheelEvent->mDeltaX = wheelEvent->mDeltaY;
+          wheelEvent->mDeltaY = deltaX;
+        }
         case WheelPrefs::ACTION_SCROLL: {
           // For scrolling of default action, we should honor the mouse wheel
           // transaction.
diff --git a/dom/events/EventStateManager.h b/dom/events/EventStateManager.h
index d0461e7fa..95ce9a907 100644
--- a/dom/events/EventStateManager.h
+++ b/dom/events/EventStateManager.h
@@ -513,7 +513,8 @@ protected:
       ACTION_SCROLL,
       ACTION_HISTORY,
       ACTION_ZOOM,
-      ACTION_LAST = ACTION_ZOOM,
+      ACTION_HSCROLL,
+      ACTION_LAST = ACTION_HSCROLL,
       // Following actions are used only by internal processing.  So, cannot
       // specified by prefs.
       ACTION_SEND_TO_PLUGIN
diff --git a/dom/fetch/Fetch.cpp b/dom/fetch/Fetch.cpp
index 5c05f3602..e2c139426 100644
--- a/dom/fetch/Fetch.cpp
+++ b/dom/fetch/Fetch.cpp
@@ -38,7 +38,6 @@
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/URLSearchParams.h"
 #include "mozilla/dom/workers/ServiceWorkerManager.h"
-#include "mozilla/Telemetry.h"
 
 #include "InternalRequest.h"
 #include "InternalResponse.h"
@@ -237,8 +236,6 @@ FetchRequest(nsIGlobalObject* aGlobal, const RequestOrUSVString& aInput,
       }
     }
 
-    Telemetry::Accumulate(Telemetry::FETCH_IS_MAINTHREAD, 1);
-
     RefPtr<MainThreadFetchResolver> resolver = new MainThreadFetchResolver(p);
     RefPtr<FetchDriver> fetch = new FetchDriver(r, principal, loadGroup);
     fetch->SetDocument(doc);
@@ -251,8 +248,6 @@ FetchRequest(nsIGlobalObject* aGlobal, const RequestOrUSVString& aInput,
     WorkerPrivate* worker = GetCurrentThreadWorkerPrivate();
     MOZ_ASSERT(worker);
 
-    Telemetry::Accumulate(Telemetry::FETCH_IS_MAINTHREAD, 0);
-
     if (worker->IsServiceWorker()) {
       r->SetSkipServiceWorker();
     }
diff --git a/dom/fetch/FetchDriver.cpp b/dom/fetch/FetchDriver.cpp
index aac79b829..1791399b7 100644
--- a/dom/fetch/FetchDriver.cpp
+++ b/dom/fetch/FetchDriver.cpp
@@ -77,9 +77,6 @@ FetchDriver::Fetch(FetchDriverObserver* aObserver)
 
   mObserver = aObserver;
 
-  Telemetry::Accumulate(Telemetry::SERVICE_WORKER_REQUEST_PASSTHROUGH,
-                        mRequest->WasCreatedByFetchEvent());
-
   // FIXME(nsm): Deal with HSTS.
 
   MOZ_RELEASE_ASSERT(!mRequest->IsSynchronous(),
diff --git a/dom/geolocation/nsGeolocation.cpp b/dom/geolocation/nsGeolocation.cpp
index 2d84a3e11..201d4d89a 100644
--- a/dom/geolocation/nsGeolocation.cpp
+++ b/dom/geolocation/nsGeolocation.cpp
@@ -382,13 +382,6 @@ nsGeolocationRequest::GetElement(nsIDOMElement * *aRequestingElement)
 NS_IMETHODIMP
 nsGeolocationRequest::Cancel()
 {
-  if (mRequester) {
-    // Record the number of denied requests for regular web content.
-    // This method is only called when the user explicitly denies the request,
-    // and is not called when the page is simply unloaded, or similar.
-    Telemetry::Accumulate(Telemetry::GEOLOCATION_REQUEST_GRANTED, mProtocolType);
-  }
-
   if (mLocator->ClearPendingRequest(this)) {
     return NS_OK;
   }
@@ -403,9 +396,6 @@ nsGeolocationRequest::Allow(JS::HandleValue aChoices)
   MOZ_ASSERT(aChoices.isUndefined());
 
   if (mRequester) {
-    // Record the number of granted requests for regular web content.
-    Telemetry::Accumulate(Telemetry::GEOLOCATION_REQUEST_GRANTED, mProtocolType + 10);
-
     // Record whether a location callback is fulfilled while the owner window
     // is not visible.
     bool isVisible = false;
@@ -415,12 +405,6 @@ nsGeolocationRequest::Allow(JS::HandleValue aChoices)
       nsCOMPtr<nsIDocument> doc = window->GetDoc();
       isVisible = doc && !doc->Hidden();
     }
-
-    if (IsWatch()) {
-      mozilla::Telemetry::Accumulate(mozilla::Telemetry::GEOLOCATION_WATCHPOSITION_VISIBLE, isVisible);
-    } else {
-      mozilla::Telemetry::Accumulate(mozilla::Telemetry::GEOLOCATION_GETCURRENTPOSITION_VISIBLE, isVisible);
-    }
   }
 
   if (mLocator->ClearPendingRequest(this)) {
@@ -1110,7 +1094,6 @@ Geolocation::Update(nsIDOMGeoPosition *aSomewhere)
     if (coords) {
       double accuracy = -1;
       coords->GetAccuracy(&accuracy);
-      mozilla::Telemetry::Accumulate(mozilla::Telemetry::GEOLOCATION_ACCURACY_EXPONENTIAL, accuracy);
     }
   }
 
@@ -1135,8 +1118,6 @@ Geolocation::NotifyError(uint16_t aErrorCode)
     return NS_OK;
   }
 
-  mozilla::Telemetry::Accumulate(mozilla::Telemetry::GEOLOCATION_ERROR, true);
-
   for (uint32_t i = mPendingCallbacks.Length(); i > 0; i--) {
     mPendingCallbacks[i-1]->NotifyErrorAndShutdown(aErrorCode);
     //NotifyErrorAndShutdown() removes the request from the array
@@ -1214,10 +1195,6 @@ Geolocation::GetCurrentPosition(GeoPositionCallback callback,
 
   // After this we hand over ownership of options to our nsGeolocationRequest.
 
-  // Count the number of requests per protocol/scheme.
-  Telemetry::Accumulate(Telemetry::GEOLOCATION_GETCURRENTPOSITION_SECURE_ORIGIN,
-                        static_cast<uint8_t>(mProtocolType));
-
   RefPtr<nsGeolocationRequest> request =
     new nsGeolocationRequest(this, Move(callback), Move(errorCallback),
                              Move(options), static_cast<uint8_t>(mProtocolType),
@@ -1292,10 +1269,6 @@ Geolocation::WatchPosition(GeoPositionCallback aCallback,
     return NS_ERROR_NOT_AVAILABLE;
   }
 
-  // Count the number of requests per protocol/scheme.
-  Telemetry::Accumulate(Telemetry::GEOLOCATION_WATCHPOSITION_SECURE_ORIGIN,
-                        static_cast<uint8_t>(mProtocolType));
-
   // The watch ID:
   *aRv = mLastWatchId++;
 
diff --git a/dom/html/HTMLFormElement.cpp b/dom/html/HTMLFormElement.cpp
index 5164391f8..0393ed3e0 100644
--- a/dom/html/HTMLFormElement.cpp
+++ b/dom/html/HTMLFormElement.cpp
@@ -38,7 +38,6 @@
 // form submission
 #include "HTMLFormSubmissionConstants.h"
 #include "mozilla/dom/FormData.h"
-#include "mozilla/Telemetry.h"
 #include "nsIFormSubmitObserver.h"
 #include "nsIObserverService.h"
 #include "nsICategoryManager.h"
@@ -957,13 +956,6 @@ HTMLFormElement::DoSecureToInsecureSubmitCheck(nsIURI* aActionURL,
   *aCancelSubmit = (buttonPressed == 1);
   uint32_t telemetryBucket =
     nsISecurityUITelemetry::WARNING_CONFIRM_POST_TO_INSECURE_FROM_SECURE;
-  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SECURITY_UI,
-                                 telemetryBucket);
-  if (!*aCancelSubmit) {
-    // The user opted to continue, so note that in the next telemetry bucket.
-    mozilla::Telemetry::Accumulate(mozilla::Telemetry::SECURITY_UI,
-                                   telemetryBucket + 1);
-  }
   return NS_OK;
 }
 
diff --git a/dom/html/HTMLInputElement.cpp b/dom/html/HTMLInputElement.cpp
index e9086933b..0b879bb9b 100644
--- a/dom/html/HTMLInputElement.cpp
+++ b/dom/html/HTMLInputElement.cpp
@@ -24,7 +24,6 @@
 #include "nsIPhonetic.h"
 
 #include "HTMLFormSubmissionConstants.h"
-#include "mozilla/Telemetry.h"
 #include "nsIControllers.h"
 #include "nsIStringBundle.h"
 #include "nsFocusManager.h"
@@ -1275,10 +1274,6 @@ HTMLInputElement::BeforeSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
         container->RadioRequiredWillChange(name, !!aValue);
       }
     }
-
-    if (aName == nsGkAtoms::webkitdirectory) {
-      Telemetry::Accumulate(Telemetry::WEBKIT_DIRECTORY_USED, true);
-    }
   }
 
   return nsGenericHTMLFormElementWithState::BeforeSetAttr(aNameSpaceID, aName,
@@ -4989,10 +4984,6 @@ HTMLInputElement::BindToTree(nsIDocument* aDocument, nsIContent* aParent,
                                  true);
       dispatcher->PostDOMEvent();
     }
-
-#ifdef EARLY_BETA_OR_EARLIER
-    Telemetry::Accumulate(Telemetry::PWMGR_PASSWORD_INPUT_IN_FORM, !!mForm);
-#endif
   }
 
   return rv;
@@ -8863,7 +8854,6 @@ HTMLInputElement::UpdateEntries(const nsTArray<OwningFileOrDirectory>& aFilesOrD
 void
 HTMLInputElement::GetWebkitEntries(nsTArray<RefPtr<FileSystemEntry>>& aSequence)
 {
-  Telemetry::Accumulate(Telemetry::BLINK_FILESYSTEM_USED, true);
   aSequence.AppendElements(mEntries);
 }
 
diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index 3954e6208..6171e1766 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -92,7 +92,6 @@
 #include "mozilla/dom/VideoTrackList.h"
 #include "mozilla/dom/TextTrack.h"
 #include "nsIContentPolicy.h"
-#include "mozilla/Telemetry.h"
 #include "DecoderDoctorDiagnostics.h"
 #include "DecoderTraits.h"
 #include "MediaContentType.h"
@@ -1902,7 +1901,6 @@ void
 HTMLMediaElement::FastSeek(double aTime, ErrorResult& aRv)
 {
   LOG(LogLevel::Debug, ("Reporting telemetry VIDEO_FASTSEEK_USED"));
-  Telemetry::Accumulate(Telemetry::VIDEO_FASTSEEK_USED, 1);
   RefPtr<Promise> tobeDropped = Seek(aTime, SeekTarget::PrevSyncPoint, aRv);
 }
 
@@ -3693,7 +3691,6 @@ HTMLMediaElement::ReportEMETelemetry()
   // Report telemetry for EME videos when a page is unloaded.
   NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
   if (mIsEncrypted && Preferences::GetBool("media.eme.enabled")) {
-    Telemetry::Accumulate(Telemetry::VIDEO_EME_PLAY_SUCCESS, mLoadedDataFired);
     LOG(LogLevel::Debug, ("%p VIDEO_EME_PLAY_SUCCESS = %s",
                        this, mLoadedDataFired ? "true" : "false"));
   }
@@ -3745,7 +3742,6 @@ HTMLMediaElement::ReportTelemetry()
     }
   }
 
-  Telemetry::Accumulate(Telemetry::VIDEO_UNLOAD_STATE, state);
   LOG(LogLevel::Debug, ("%p VIDEO_UNLOAD_STATE = %d", this, state));
 
   FrameStatisticsData data;
@@ -3761,8 +3757,6 @@ HTMLMediaElement::ReportTelemetry()
         uint32_t percentage = 100 * data.mDroppedFrames / data.mParsedFrames;
         LOG(LogLevel::Debug,
             ("Reporting telemetry DROPPED_FRAMES_IN_VIDEO_PLAYBACK"));
-        Telemetry::Accumulate(Telemetry::VIDEO_DROPPED_FRAMES_PROPORTION,
-                              percentage);
       }
     }
   }
@@ -3774,10 +3768,8 @@ HTMLMediaElement::ReportTelemetry()
     double hiddenPlayTime = mHiddenPlayTime.Total();
     double videoDecodeSuspendTime = mVideoDecodeSuspendTime.Total();
 
-    Telemetry::Accumulate(Telemetry::VIDEO_PLAY_TIME_MS, SECONDS_TO_MS(playTime));
     LOG(LogLevel::Debug, ("%p VIDEO_PLAY_TIME_MS = %f", this, playTime));
 
-    Telemetry::Accumulate(Telemetry::VIDEO_HIDDEN_PLAY_TIME_MS, SECONDS_TO_MS(hiddenPlayTime));
     LOG(LogLevel::Debug, ("%p VIDEO_HIDDEN_PLAY_TIME_MS = %f", this, hiddenPlayTime));
 
     if (playTime > 0.0) {
@@ -3804,24 +3796,11 @@ HTMLMediaElement::ReportTelemetry()
       key.AppendASCII(resolution);
 
       uint32_t hiddenPercentage = uint32_t(hiddenPlayTime / playTime * 100.0 + 0.5);
-      Telemetry::Accumulate(Telemetry::VIDEO_HIDDEN_PLAY_TIME_PERCENTAGE,
-                            key,
-                            hiddenPercentage);
-      // Also accumulate all percentages in an "All" key.
-      Telemetry::Accumulate(Telemetry::VIDEO_HIDDEN_PLAY_TIME_PERCENTAGE,
-                            NS_LITERAL_CSTRING("All"),
-                            hiddenPercentage);
       LOG(LogLevel::Debug, ("%p VIDEO_HIDDEN_PLAY_TIME_PERCENTAGE = %u, keys: '%s' and 'All'",
                             this, hiddenPercentage, key.get()));
 
       uint32_t videoDecodeSuspendPercentage =
         uint32_t(videoDecodeSuspendTime / playTime * 100.0 + 0.5);
-      Telemetry::Accumulate(Telemetry::VIDEO_INFERRED_DECODE_SUSPEND_PERCENTAGE,
-                            key,
-                            videoDecodeSuspendPercentage);
-      Telemetry::Accumulate(Telemetry::VIDEO_INFERRED_DECODE_SUSPEND_PERCENTAGE,
-                            NS_LITERAL_CSTRING("All"),
-                            videoDecodeSuspendPercentage);
       LOG(LogLevel::Debug, ("%p VIDEO_INFERRED_DECODE_SUSPEND_PERCENTAGE = %u, keys: '%s' and 'All'",
                             this, videoDecodeSuspendPercentage, key.get()));
 
@@ -3832,24 +3811,12 @@ HTMLMediaElement::ReportTelemetry()
                                       / 1000.0
                                       + 0.5,
                                       UINT32_MAX));
-        Telemetry::Accumulate(Telemetry::VIDEO_INTER_KEYFRAME_AVERAGE_MS,
-                              key,
-                              average_ms);
-        Telemetry::Accumulate(Telemetry::VIDEO_INTER_KEYFRAME_AVERAGE_MS,
-                              NS_LITERAL_CSTRING("All"),
-                              average_ms);
         LOG(LogLevel::Debug, ("%p VIDEO_INTER_KEYFRAME_AVERAGE_MS = %u, keys: '%s' and 'All'",
                               this, average_ms, key.get()));
 
         uint32_t max_ms =
           uint32_t(std::min<uint64_t>((data.mInterKeyFrameMax_us + 500) / 1000,
                                       UINT32_MAX));
-        Telemetry::Accumulate(Telemetry::VIDEO_INTER_KEYFRAME_MAX_MS,
-                              key,
-                              max_ms);
-        Telemetry::Accumulate(Telemetry::VIDEO_INTER_KEYFRAME_MAX_MS,
-                              NS_LITERAL_CSTRING("All"),
-                              max_ms);
         LOG(LogLevel::Debug, ("%p VIDEO_INTER_KEYFRAME_MAX_MS = %u, keys: '%s' and 'All'",
                               this, max_ms, key.get()));
       } else {
@@ -3858,12 +3825,6 @@ HTMLMediaElement::ReportTelemetry()
         // decode-suspend delay (showing recovery would be difficult).
         uint32_t suspendDelay_ms = MediaPrefs::MDSMSuspendBackgroundVideoDelay();
         if (uint32_t(playTime * 1000.0) > suspendDelay_ms) {
-          Telemetry::Accumulate(Telemetry::VIDEO_INTER_KEYFRAME_MAX_MS,
-                                key,
-                                0);
-          Telemetry::Accumulate(Telemetry::VIDEO_INTER_KEYFRAME_MAX_MS,
-                                NS_LITERAL_CSTRING("All"),
-                                0);
           LOG(LogLevel::Debug, ("%p VIDEO_INTER_KEYFRAME_MAX_MS = 0 (only 1 keyframe), keys: '%s' and 'All'",
                                 this, key.get()));
         }
@@ -6860,97 +6821,6 @@ HTMLMediaElement::MarkAsContentSource(CallerAPI aAPI)
 {
   const bool isVisible = mVisibilityState != Visibility::APPROXIMATELY_NONVISIBLE;
 
-  if (isVisible) {
-    // 0 = ALL_VISIBLE
-    Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 0);
-  } else {
-    // 1 = ALL_INVISIBLE
-    Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 1);
-
-    if (IsInUncomposedDoc()) {
-      // 0 = ALL_IN_TREE
-      Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 0);
-    } else {
-      // 1 = ALL_NOT_IN_TREE
-      Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 1);
-    }
-  }
-
-  switch (aAPI) {
-    case CallerAPI::DRAW_IMAGE: {
-      if (isVisible) {
-        // 2 = drawImage_VISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 2);
-      } else {
-        // 3 = drawImage_INVISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 3);
-
-        if (IsInUncomposedDoc()) {
-          // 2 = drawImage_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 2);
-        } else {
-          // 3 = drawImage_NOT_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 3);
-        }
-      }
-      break;
-    }
-    case CallerAPI::CREATE_PATTERN: {
-      if (isVisible) {
-        // 4 = createPattern_VISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 4);
-      } else {
-        // 5 = createPattern_INVISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 5);
-
-        if (IsInUncomposedDoc()) {
-          // 4 = createPattern_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 4);
-        } else {
-          // 5 = createPattern_NOT_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 5);
-        }
-      }
-      break;
-    }
-    case CallerAPI::CREATE_IMAGEBITMAP: {
-      if (isVisible) {
-        // 6 = createImageBitmap_VISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 6);
-      } else {
-        // 7 = createImageBitmap_INVISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 7);
-
-        if (IsInUncomposedDoc()) {
-          // 6 = createImageBitmap_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 6);
-        } else {
-          // 7 = createImageBitmap_NOT_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 7);
-        }
-      }
-      break;
-    }
-    case CallerAPI::CAPTURE_STREAM: {
-      if (isVisible) {
-        // 8 = captureStream_VISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 8);
-      } else {
-        // 9 = captureStream_INVISIBLE
-        Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE, 9);
-
-        if (IsInUncomposedDoc()) {
-          // 8 = captureStream_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 8);
-        } else {
-          // 9 = captureStream_NOT_IN_TREE
-          Telemetry::Accumulate(Telemetry::VIDEO_AS_CONTENT_SOURCE_IN_TREE_OR_NOT, 9);
-        }
-      }
-      break;
-    }
-  }
-
   LOG(LogLevel::Debug,
       ("%p Log VIDEO_AS_CONTENT_SOURCE: visibility = %u, API: '%d' and 'All'",
        this, isVisible, aAPI));
diff --git a/dom/html/ImageDocument.cpp b/dom/html/ImageDocument.cpp
index 200bb5d46..f83a804be 100644
--- a/dom/html/ImageDocument.cpp
+++ b/dom/html/ImageDocument.cpp
@@ -40,12 +40,14 @@
 #include "nsThreadUtils.h"
 #include "nsIScrollableFrame.h"
 #include "nsContentUtils.h"
+#include "nsCSSParser.h" // for CSS colors on the background
 #include "mozilla/dom/Element.h"
 #include "mozilla/Preferences.h"
 #include <algorithm>
 
 #define AUTOMATIC_IMAGE_RESIZING_PREF "browser.enable_automatic_image_resizing"
 #define CLICK_IMAGE_RESIZING_PREF "browser.enable_click_image_resizing"
+#define STANDALONE_IMAGE_BACKGROUND_COLOR_PREF "browser.display.standalone_images.background_color"
 //XXX A hack needed for Firefox's site specific zoom.
 #define SITE_SPECIFIC_ZOOM "browser.zoom.siteSpecific"
 
@@ -170,6 +172,8 @@ ImageDocument::Init()
   mClickResizingEnabled = Preferences::GetBool(CLICK_IMAGE_RESIZING_PREF);
   mShouldResize = mResizeImageByDefault;
   mFirstResize = true;
+  
+  mBackgroundColor = Preferences::GetString(STANDALONE_IMAGE_BACKGROUND_COLOR_PREF);
 
   return NS_OK;
 }
@@ -682,9 +686,22 @@ ImageDocument::CreateSyntheticDocument()
   mImageContent->SetAttr(kNameSpaceID_None, nsGkAtoms::src, srcString, false);
   mImageContent->SetAttr(kNameSpaceID_None, nsGkAtoms::alt, srcString, false);
 
+  // Implement mechanism for custom background color from pref.
+  if (!mBackgroundColor.IsEmpty()) {
+    nsCSSValue color;
+    nsCSSParser parser;
+    if (parser.ParseColorString(mBackgroundColor, nullptr, 0, color)) {
+      nsAutoString styleAttr(NS_LITERAL_STRING("background-color: "));
+      styleAttr.Append(mBackgroundColor);
+      body->SetAttr(kNameSpaceID_None, nsGkAtoms::style, styleAttr, false);
+    }
+  }
+
   body->AppendChildTo(mImageContent, false);
   imageLoader->SetLoadingEnabled(true);
 
+  UpdateTitleAndCharset();
+  
   return NS_OK;
 }
 
diff --git a/dom/html/ImageDocument.h b/dom/html/ImageDocument.h
index fdf2a00a8..945317314 100644
--- a/dom/html/ImageDocument.h
+++ b/dom/html/ImageDocument.h
@@ -112,6 +112,9 @@ protected:
   float                         mVisibleHeight;
   int32_t                       mImageWidth;
   int32_t                       mImageHeight;
+  
+  // Holds the custom background color for stand-alone images
+  nsAutoString                  mBackgroundColor;
 
   bool                          mResizeImageByDefault;
   bool                          mClickResizingEnabled;
diff --git a/dom/html/TextTrackManager.cpp b/dom/html/TextTrackManager.cpp
index 8110dab29..4266575f7 100644
--- a/dom/html/TextTrackManager.cpp
+++ b/dom/html/TextTrackManager.cpp
@@ -12,7 +12,6 @@
 #include "mozilla/dom/TextTrackCue.h"
 #include "mozilla/dom/Event.h"
 #include "mozilla/ClearOnShutdown.h"
-#include "mozilla/Telemetry.h"
 #include "nsComponentManagerUtils.h"
 #include "nsVariant.h"
 #include "nsVideoFrame.h"
@@ -824,24 +823,13 @@ TextTrackManager::NotifyReset()
 void
 TextTrackManager::ReportTelemetryForTrack(TextTrack* aTextTrack) const
 {
-  MOZ_ASSERT(NS_IsMainThread());
-  MOZ_ASSERT(aTextTrack);
-  MOZ_ASSERT(mTextTracks->Length() > 0);
-
-  TextTrackKind kind = aTextTrack->Kind();
-  Telemetry::Accumulate(Telemetry::WEBVTT_TRACK_KINDS, uint32_t(kind));
+/* STUB */
 }
 
 void
 TextTrackManager::ReportTelemetryForCue()
 {
-  MOZ_ASSERT(NS_IsMainThread());
-  MOZ_ASSERT(!mNewCues->IsEmpty() || !mLastActiveCues->IsEmpty());
-
-  if (!mCueTelemetryReported) {
-    Telemetry::Accumulate(Telemetry::WEBVTT_USED_VTT_CUES, 1);
-    mCueTelemetryReported = true;
-  }
+/* STUB */
 }
 
 } // namespace dom
diff --git a/dom/html/nsHTMLDocument.cpp b/dom/html/nsHTMLDocument.cpp
index 69e710242..d64c27727 100644
--- a/dom/html/nsHTMLDocument.cpp
+++ b/dom/html/nsHTMLDocument.cpp
@@ -886,7 +886,7 @@ nsHTMLDocument::GetDomain(nsAString& aDomain)
   nsCOMPtr<nsIURI> uri = GetDomainURI();
 
   if (!uri) {
-    SetDOMStringToNull(aDomain);
+    aDomain.Truncate();
     return NS_OK;
   }
 
@@ -896,8 +896,8 @@ nsHTMLDocument::GetDomain(nsAString& aDomain)
     CopyUTF8toUTF16(hostName, aDomain);
   } else {
     // If we can't get the host from the URI (e.g. about:, javascript:,
-    // etc), just return an null string.
-    SetDOMStringToNull(aDomain);
+    // etc), just return an empty string.
+    aDomain.Truncate();
   }
   return NS_OK;
 }
diff --git a/dom/html/nsTextEditorState.cpp b/dom/html/nsTextEditorState.cpp
index 187afb66d..0b4cb1920 100644
--- a/dom/html/nsTextEditorState.cpp
+++ b/dom/html/nsTextEditorState.cpp
@@ -47,7 +47,6 @@
 #include "mozilla/dom/HTMLInputElement.h"
 #include "nsNumberControlFrame.h"
 #include "nsFrameSelection.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/layers/ScrollInputMethods.h"
 
 using namespace mozilla;
@@ -585,9 +584,6 @@ nsTextInputSelectionImpl::CompleteScroll(bool aForward)
   if (!mScrollFrame)
     return NS_ERROR_NOT_INITIALIZED;
 
-  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
-      (uint32_t) ScrollInputMethod::MainThreadCompleteScroll);
-
   mScrollFrame->ScrollBy(nsIntPoint(0, aForward ? 1 : -1),
                          nsIScrollableFrame::WHOLE,
                          nsIScrollableFrame::INSTANT);
@@ -640,9 +636,6 @@ nsTextInputSelectionImpl::ScrollPage(bool aForward)
   if (!mScrollFrame)
     return NS_ERROR_NOT_INITIALIZED;
 
-  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
-      (uint32_t) ScrollInputMethod::MainThreadScrollPage);
-
   mScrollFrame->ScrollBy(nsIntPoint(0, aForward ? 1 : -1),
                          nsIScrollableFrame::PAGES,
                          nsIScrollableFrame::SMOOTH);
@@ -655,9 +648,6 @@ nsTextInputSelectionImpl::ScrollLine(bool aForward)
   if (!mScrollFrame)
     return NS_ERROR_NOT_INITIALIZED;
 
-  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
-      (uint32_t) ScrollInputMethod::MainThreadScrollLine);
-
   mScrollFrame->ScrollBy(nsIntPoint(0, aForward ? 1 : -1),
                          nsIScrollableFrame::LINES,
                          nsIScrollableFrame::SMOOTH);
@@ -670,9 +660,6 @@ nsTextInputSelectionImpl::ScrollCharacter(bool aRight)
   if (!mScrollFrame)
     return NS_ERROR_NOT_INITIALIZED;
 
-  mozilla::Telemetry::Accumulate(mozilla::Telemetry::SCROLL_INPUT_METHODS,
-      (uint32_t) ScrollInputMethod::MainThreadScrollCharacter);
-
   mScrollFrame->ScrollBy(nsIntPoint(aRight ? 1 : -1, 0),
                          nsIScrollableFrame::LINES,
                          nsIScrollableFrame::SMOOTH);
diff --git a/dom/ipc/ContentParent.cpp b/dom/ipc/ContentParent.cpp
index 0a07147bf..5c6aadb77 100644
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -1718,9 +1718,6 @@ ContentParent::ActorDestroy(ActorDestroyReason why)
     props->SetPropertyAsUint64(NS_LITERAL_STRING("childID"), mChildID);
 
     if (AbnormalShutdown == why) {
-      Telemetry::Accumulate(Telemetry::SUBPROCESS_ABNORMAL_ABORT,
-                            NS_LITERAL_CSTRING("content"), 1);
-
       props->SetPropertyAsBool(NS_LITERAL_STRING("abnormal"), true);
     }
     nsAutoString cpId;
@@ -4778,7 +4775,7 @@ bool
 ContentParent::RecvAccumulateChildHistogram(
                 InfallibleTArray<Accumulation>&& aAccumulations)
 {
-  Telemetry::AccumulateChild(GeckoProcessType_Content, aAccumulations);
+  /* STUB */
   return true;
 }
 
@@ -4786,6 +4783,6 @@ bool
 ContentParent::RecvAccumulateChildKeyedHistogram(
                 InfallibleTArray<KeyedAccumulation>&& aAccumulations)
 {
-  Telemetry::AccumulateChildKeyed(GeckoProcessType_Content, aAccumulations);
+  /* STUB */
   return true;
 }
diff --git a/dom/ipc/TabChild.cpp b/dom/ipc/TabChild.cpp
index 705799c54..244fa9969 100644
--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -2395,7 +2395,6 @@ TabChild::RecvSetDocShellIsActive(const bool& aIsActive,
         root->SchedulePaint();
       }
 
-      Telemetry::AutoTimer<Telemetry::TABCHILD_PAINT_TIME> timer;
       // If we need to repaint, let's do that right away. No sense waiting until
       // we get back to the event loop again. We suppress the display port so that
       // we only paint what's visible. This ensures that the tab we're switching
diff --git a/dom/locales/en-US/chrome/dom/dom.properties b/dom/locales/en-US/chrome/dom/dom.properties
index ec0356c04..0472979d7 100644
--- a/dom/locales/en-US/chrome/dom/dom.properties
+++ b/dom/locales/en-US/chrome/dom/dom.properties
@@ -195,8 +195,6 @@ IgnoringWillChangeOverBudgetWarning=Will-change memory consumption is too high.
 HittingMaxWorkersPerDomain2=A Worker could not be started immediately because other documents in the same origin are already using the maximum number of workers. The Worker is now queued and will be started after some of the other workers have completed.
 # LOCALIZATION NOTE: Do not translate "setVelocity", "PannerNode", "AudioListener", "speedOfSound" and "dopplerFactor"
 PannerNodeDopplerWarning=Use of setVelocity on the PannerNode and AudioListener, and speedOfSound and dopplerFactor on the AudioListener are deprecated and those members will be removed. For more help https://developer.mozilla.org/en-US/docs/Web/API/AudioListener#Deprecated_features
-# LOCALIZATION NOTE: Do not translate "Application Cache API", "AppCache" and "ServiceWorker".
-AppCacheWarning=The Application Cache API (AppCache) is deprecated and will be removed at a future date.  Please consider using ServiceWorker for offline support.
 # LOCALIZATION NOTE: Do not translate "Worker".
 EmptyWorkerSourceWarning=Attempting to create a Worker from an empty source. This is probably unintentional.
 WebrtcDeprecatedPrefixWarning=WebRTC interfaces with the “moz” prefix (mozRTCPeerConnection, mozRTCSessionDescription, mozRTCIceCandidate) have been deprecated.
diff --git a/dom/locales/en-US/chrome/security/security.properties b/dom/locales/en-US/chrome/security/security.properties
index c0b80996c..8efdb0a6d 100644
--- a/dom/locales/en-US/chrome/security/security.properties
+++ b/dom/locales/en-US/chrome/security/security.properties
@@ -8,6 +8,7 @@ BlockMixedActiveContent = Blocked loading mixed active content “%1$S”
 CORSDisabled=Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at %1$S. (Reason: CORS disabled).
 CORSRequestNotHttp=Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at %1$S. (Reason: CORS request not http).
 CORSMissingAllowOrigin=Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at %1$S. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).
+CORSMultipleAllowOriginNotAllowed=Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at %1$S. (Reason: Multiple CORS headers ‘Access-Control-Allow-Origin’ not allowed).
 CORSAllowOriginNotMatchingOrigin=Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at %1$S. (Reason: CORS header ‘Access-Control-Allow-Origin’ does not match ‘%2$S’).
 CORSNotSupportingCredentials=Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at ‘%1$S’. (Reason: Credential is not supported if the CORS header ‘Access-Control-Allow-Origin’ is ‘*’).
 CORSMethodNotFound=Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at %1$S. (Reason: Did not find method in CORS header ‘Access-Control-Allow-Methods’).
diff --git a/dom/media/AudioStream.cpp b/dom/media/AudioStream.cpp
index 54cf7b965..896dee407 100644
--- a/dom/media/AudioStream.cpp
+++ b/dom/media/AudioStream.cpp
@@ -14,7 +14,6 @@
 #include "mozilla/Mutex.h"
 #include "mozilla/Sprintf.h"
 #include <algorithm>
-#include "mozilla/Telemetry.h"
 #include "CubebUtils.h"
 #include "nsPrintfCString.h"
 #include "gfxPrefs.h"
@@ -378,8 +377,6 @@ AudioStream::OpenCubeb(cubeb* aContext, cubeb_stream_params& aParams,
   TimeDuration timeDelta = TimeStamp::Now() - aStartTime;
   LOG("creation time %sfirst: %u ms", aIsFirst ? "" : "not ",
       (uint32_t) timeDelta.ToMilliseconds());
-  Telemetry::Accumulate(aIsFirst ? Telemetry::AUDIOSTREAM_FIRST_OPEN_MS :
-      Telemetry::AUDIOSTREAM_LATER_OPEN_MS, timeDelta.ToMilliseconds());
 
   return NS_OK;
 }
diff --git a/dom/media/Benchmark.cpp b/dom/media/Benchmark.cpp
index fdbedeca5..7394f8036 100644
--- a/dom/media/Benchmark.cpp
+++ b/dom/media/Benchmark.cpp
@@ -11,7 +11,6 @@
 #include "PDMFactory.h"
 #include "WebMDemuxer.h"
 #include "mozilla/Preferences.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/dom/ContentChild.h"
 
 #ifndef MOZ_WIDGET_ANDROID
@@ -68,7 +67,6 @@ VP9Benchmark::IsVP9DecodeFast()
           Preferences::SetUint(sBenchmarkFpsPref, aDecodeFps);
           Preferences::SetUint(sBenchmarkFpsVersionCheck, sBenchmarkVersionID);
         }
-        Telemetry::Accumulate(Telemetry::ID::VIDEO_VP9_BENCHMARK_FPS, aDecodeFps);
       },
       []() { });
   }
diff --git a/dom/media/CubebUtils.cpp b/dom/media/CubebUtils.cpp
index fe94264ee..93792e63b 100644
--- a/dom/media/CubebUtils.cpp
+++ b/dom/media/CubebUtils.cpp
@@ -248,14 +248,9 @@ void ReportCubebBackendUsed()
   bool foundBackend = false;
   for (uint32_t i = 0; i < ArrayLength(AUDIOSTREAM_BACKEND_ID_STR); i++) {
     if (!strcmp(cubeb_get_backend_id(sCubebContext), AUDIOSTREAM_BACKEND_ID_STR[i])) {
-      Telemetry::Accumulate(Telemetry::AUDIOSTREAM_BACKEND_USED, i);
       foundBackend = true;
     }
   }
-  if (!foundBackend) {
-    Telemetry::Accumulate(Telemetry::AUDIOSTREAM_BACKEND_USED,
-                          CUBEB_BACKEND_UNKNOWN);
-  }
 }
 
 void ReportCubebStreamInitFailure(bool aIsFirst)
@@ -267,9 +262,6 @@ void ReportCubebStreamInitFailure(bool aIsFirst)
     // failures to open multiple streams in a process over time.
     return;
   }
-  Telemetry::Accumulate(Telemetry::AUDIOSTREAM_BACKEND_USED,
-                        aIsFirst ? CUBEB_BACKEND_INIT_FAILURE_FIRST
-                                 : CUBEB_BACKEND_INIT_FAILURE_OTHER);
 }
 
 uint32_t GetCubebPlaybackLatencyInMilliseconds()
diff --git a/dom/media/DecoderTraits.cpp b/dom/media/DecoderTraits.cpp
index ddd35fe0d..56ebd9ce9 100644
--- a/dom/media/DecoderTraits.cpp
+++ b/dom/media/DecoderTraits.cpp
@@ -288,7 +288,7 @@ CanHandleMediaType(const MediaContentType& aType,
   MOZ_ASSERT(NS_IsMainThread());
 
   if (IsHttpLiveStreamingType(aType.GetMIMEType())) {
-    Telemetry::Accumulate(Telemetry::MEDIA_HLS_CANPLAY_REQUESTED, true);
+    /* Telemetry STUB */
   }
 
   if (aType.HaveCodecs()) {
@@ -433,11 +433,6 @@ InstantiateDecoder(const nsACString& aType,
   }
 #endif
 
-  if (IsHttpLiveStreamingType(aType)) {
-    // We don't have an HLS decoder.
-    Telemetry::Accumulate(Telemetry::MEDIA_HLS_DECODER_SUCCESS, false);
-  }
-
   return nullptr;
 }
 
diff --git a/dom/media/MediaDecoder.cpp b/dom/media/MediaDecoder.cpp
index 9334d1bcb..d027818de 100644
--- a/dom/media/MediaDecoder.cpp
+++ b/dom/media/MediaDecoder.cpp
@@ -877,7 +877,6 @@ MediaDecoder::EnsureTelemetryReported()
   }
   for (const nsCString& codec : codecs) {
     DECODER_LOG("Telemetry MEDIA_CODEC_USED= '%s'", codec.get());
-    Telemetry::Accumulate(Telemetry::ID::MEDIA_CODEC_USED, codec);
   }
 
   mTelemetryReported = true;
diff --git a/dom/media/MediaDecoderStateMachine.cpp b/dom/media/MediaDecoderStateMachine.cpp
index c586139ad..5bc1d95ef 100644
--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -1178,40 +1178,7 @@ ReportRecoveryTelemetry(const TimeStamp& aRecoveryStart,
                         const MediaInfo& aMediaInfo,
                         bool aIsHardwareAccelerated)
 {
-  MOZ_ASSERT(NS_IsMainThread());
-  if (!aMediaInfo.HasVideo()) {
-    return;
-  }
-
-  // Keyed by audio+video or video alone, hardware acceleration,
-  // and by a resolution range.
-  nsCString key(aMediaInfo.HasAudio() ? "AV" : "V");
-  key.AppendASCII(aIsHardwareAccelerated ? "(hw)," : ",");
-  static const struct { int32_t mH; const char* mRes; } sResolutions[] = {
-    {  240, "0-240" },
-    {  480, "241-480" },
-    {  720, "481-720" },
-    { 1080, "721-1080" },
-    { 2160, "1081-2160" }
-  };
-  const char* resolution = "2161+";
-  int32_t height = aMediaInfo.mVideo.mImage.height;
-  for (const auto& res : sResolutions) {
-    if (height <= res.mH) {
-      resolution = res.mRes;
-      break;
-    }
-  }
-  key.AppendASCII(resolution);
-
-  TimeDuration duration = TimeStamp::Now() - aRecoveryStart;
-  double duration_ms = duration.ToMilliseconds();
-  Telemetry::Accumulate(Telemetry::VIDEO_SUSPEND_RECOVERY_TIME_MS,
-                        key,
-                        uint32_t(duration_ms + 0.5));
-  Telemetry::Accumulate(Telemetry::VIDEO_SUSPEND_RECOVERY_TIME_MS,
-                        NS_LITERAL_CSTRING("All"),
-                        uint32_t(duration_ms + 0.5));
+/* STUB */
 }
 
 void
diff --git a/dom/media/MediaManager.cpp b/dom/media/MediaManager.cpp
index ba6b4cd47..baaf45416 100644
--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -32,7 +32,6 @@
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsIInputStream.h"
 #include "nsILineInputStream.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/Types.h"
 #include "mozilla/PeerIdentity.h"
 #include "mozilla/dom/ContentChild.h"
@@ -2058,28 +2057,6 @@ MediaManager::GetUserMedia(nsPIDOMWindowInner* aWindow,
                       host.LowerCaseEqualsLiteral("127.0.0.1") ||
                       host.LowerCaseEqualsLiteral("::1"));
 
-  // Record telemetry about whether the source of the call was secure, i.e.,
-  // privileged or HTTPS.  We may handle other cases
-if (privileged) {
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_SECURE_ORIGIN,
-                          (uint32_t) GetUserMediaSecurityState::Privileged);
-  } else if (isHTTPS) {
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_SECURE_ORIGIN,
-                          (uint32_t) GetUserMediaSecurityState::HTTPS);
-  } else if (isFile) {
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_SECURE_ORIGIN,
-                          (uint32_t) GetUserMediaSecurityState::File);
-  } else if (isApp) {
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_SECURE_ORIGIN,
-                          (uint32_t) GetUserMediaSecurityState::App);
-  } else if (isLocalhost) {
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_SECURE_ORIGIN,
-                          (uint32_t) GetUserMediaSecurityState::Localhost);
-  } else {
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_SECURE_ORIGIN,
-                          (uint32_t) GetUserMediaSecurityState::Other);
-  }
-
   nsCString origin;
   rv = nsPrincipal::GetOriginForURI(docURI, origin);
   if (NS_WARN_IF(NS_FAILED(rv))) {
@@ -2098,8 +2075,6 @@ if (privileged) {
     videoType = StringToEnum(dom::MediaSourceEnumValues::strings,
                              vc.mMediaSource,
                              MediaSourceEnum::Other);
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_TYPE,
-                          (uint32_t) videoType);
     switch (videoType) {
       case MediaSourceEnum::Camera:
         break;
@@ -2182,8 +2157,6 @@ if (privileged) {
       ac.mMediaSource.AssignASCII(EnumToASCII(dom::MediaSourceEnumValues::strings,
                                               audioType));
     }
-    Telemetry::Accumulate(Telemetry::WEBRTC_GET_USER_MEDIA_TYPE,
-                          (uint32_t) audioType);
 
     switch (audioType) {
       case MediaSourceEnum::Microphone:
diff --git a/dom/media/VideoUtils.cpp b/dom/media/VideoUtils.cpp
index 5c00e54bc..b1a202c03 100644
--- a/dom/media/VideoUtils.cpp
+++ b/dom/media/VideoUtils.cpp
@@ -6,7 +6,6 @@
 
 #include "mozilla/Base64.h"
 #include "mozilla/TaskQueue.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/Function.h"
 
 #include "MediaContentType.h"
@@ -248,24 +247,6 @@ ExtractH264CodecDetails(const nsAString& aCodec,
     aLevel *= 10;
   }
 
-  // Capture the constraint_set flag value for the purpose of Telemetry.
-  // We don't NS_ENSURE_SUCCESS here because ExtractH264CodecDetails doesn't
-  // care about this, but we make sure constraints is above 4 (constraint_set5_flag)
-  // otherwise collect 0 for unknown.
-  uint8_t constraints = PromiseFlatString(Substring(aCodec, 7, 2)).ToInteger(&rv, 16);
-  Telemetry::Accumulate(Telemetry::VIDEO_CANPLAYTYPE_H264_CONSTRAINT_SET_FLAG,
-                        constraints >= 4 ? constraints : 0);
-
-  // 244 is the highest meaningful profile value (High 4:4:4 Intra Profile)
-  // that can be represented as single hex byte, otherwise collect 0 for unknown.
-  Telemetry::Accumulate(Telemetry::VIDEO_CANPLAYTYPE_H264_PROFILE,
-                        aProfile <= 244 ? aProfile : 0);
-
-  // Make sure aLevel represents a value between levels 1 and 5.2,
-  // otherwise collect 0 for unknown.
-  Telemetry::Accumulate(Telemetry::VIDEO_CANPLAYTYPE_H264_LEVEL,
-                        (aLevel >= 10 && aLevel <= 52) ? aLevel : 0);
-
   return true;
 }
 
diff --git a/dom/media/eme/DetailedPromise.cpp b/dom/media/eme/DetailedPromise.cpp
index 5893bea2e..d443e3336 100644
--- a/dom/media/eme/DetailedPromise.cpp
+++ b/dom/media/eme/DetailedPromise.cpp
@@ -96,9 +96,6 @@ DetailedPromise::MaybeReportTelemetry(Status aStatus)
   uint32_t latency = (TimeStamp::Now() - mStartTime).ToMilliseconds();
   EME_LOG("%s %s latency %ums reported via telemetry", mName.get(),
           ((aStatus == Succeeded) ? "succcess" : "failure"), latency);
-  Telemetry::ID tid = (aStatus == Succeeded) ? mSuccessLatencyProbe.Value()
-                                             : mFailureLatencyProbe.Value();
-  Telemetry::Accumulate(tid, latency);
 }
 
 } // namespace dom
diff --git a/dom/media/eme/MediaKeySession.cpp b/dom/media/eme/MediaKeySession.cpp
index d5eff3f77..9c002b5ba 100644
--- a/dom/media/eme/MediaKeySession.cpp
+++ b/dom/media/eme/MediaKeySession.cpp
@@ -315,9 +315,6 @@ MediaKeySession::GenerateRequest(const nsAString& aInitDataType,
 
   // Note: Remaining steps of generateRequest method continue in CDM.
 
-  Telemetry::Accumulate(Telemetry::VIDEO_CDM_GENERATE_REQUEST_CALLED,
-                        ToCDMTypeTelemetryEnum(mKeySystem));
-
   // Convert initData to base64 for easier logging.
   // Note: CreateSession() Move()s the data out of the array, so we have
   // to copy it here.
diff --git a/dom/media/eme/MediaKeys.cpp b/dom/media/eme/MediaKeys.cpp
index eedd675e4..fea548698 100644
--- a/dom/media/eme/MediaKeys.cpp
+++ b/dom/media/eme/MediaKeys.cpp
@@ -13,7 +13,6 @@
 #include "mozilla/dom/MediaKeySession.h"
 #include "mozilla/dom/DOMException.h"
 #include "mozilla/dom/UnionTypes.h"
-#include "mozilla/Telemetry.h"
 #include "GMPCDMProxy.h"
 #ifdef MOZ_WIDGET_ANDROID
 #include "mozilla/MediaDrmCDMProxy.h"
@@ -457,7 +456,6 @@ MediaKeys::OnCDMCreated(PromiseId aId, const nsACString& aNodeId, const uint32_t
                                         mKeySystem,
                                         MediaKeySystemStatus::Cdm_created);
 
-  Telemetry::Accumulate(Telemetry::VIDEO_CDM_CREATED, ToCDMTypeTelemetryEnum(mKeySystem));
 }
 
 static bool
diff --git a/dom/media/fmp4/MP4Demuxer.cpp b/dom/media/fmp4/MP4Demuxer.cpp
index 70b176699..5a637b003 100644
--- a/dom/media/fmp4/MP4Demuxer.cpp
+++ b/dom/media/fmp4/MP4Demuxer.cpp
@@ -81,35 +81,11 @@ private:
 bool
 AccumulateSPSTelemetry(const MediaByteBuffer* aExtradata)
 {
+  // XXX: Do we still need this without telemetry?
   mp4_demuxer::SPSData spsdata;
   if (mp4_demuxer::H264::DecodeSPSFromExtraData(aExtradata, spsdata)) {
-    uint8_t constraints = (spsdata.constraint_set0_flag ? (1 << 0) : 0) |
-                          (spsdata.constraint_set1_flag ? (1 << 1) : 0) |
-                          (spsdata.constraint_set2_flag ? (1 << 2) : 0) |
-                          (spsdata.constraint_set3_flag ? (1 << 3) : 0) |
-                          (spsdata.constraint_set4_flag ? (1 << 4) : 0) |
-                          (spsdata.constraint_set5_flag ? (1 << 5) : 0);
-    Telemetry::Accumulate(Telemetry::VIDEO_DECODED_H264_SPS_CONSTRAINT_SET_FLAG,
-                          constraints);
-
-    // Collect profile_idc values up to 244, otherwise 0 for unknown.
-    Telemetry::Accumulate(Telemetry::VIDEO_DECODED_H264_SPS_PROFILE,
-                          spsdata.profile_idc <= 244 ? spsdata.profile_idc : 0);
-
-    // Make sure level_idc represents a value between levels 1 and 5.2,
-    // otherwise collect 0 for unknown level.
-    Telemetry::Accumulate(Telemetry::VIDEO_DECODED_H264_SPS_LEVEL,
-                          (spsdata.level_idc >= 10 && spsdata.level_idc <= 52) ?
-                          spsdata.level_idc : 0);
-
-    // max_num_ref_frames should be between 0 and 16, anything larger will
-    // be treated as invalid.
-    Telemetry::Accumulate(Telemetry::VIDEO_H264_SPS_MAX_NUM_REF_FRAMES,
-                          std::min(spsdata.max_num_ref_frames, 17u));
-
     return false;
   }
-
   return true;
 }
 
@@ -349,8 +325,13 @@ MP4TrackDemuxer::GetNextSample()
   if (sample->mCrypto.mValid) {
     nsAutoPtr<MediaRawDataWriter> writer(sample->CreateWriter());
     writer->mCrypto.mMode = mInfo->mCrypto.mMode;
-    writer->mCrypto.mIVSize = mInfo->mCrypto.mIVSize;
-    writer->mCrypto.mKeyId.AppendElements(mInfo->mCrypto.mKeyId);
+
+    // Only use the default key parsed from the moov if we haven't already got
+    // one from the sample group description.
+    if (writer->mCrypto.mKeyId.Length() == 0) {
+      writer->mCrypto.mIVSize = mInfo->mCrypto.mIVSize;
+      writer->mCrypto.mKeyId.AppendElements(mInfo->mCrypto.mKeyId);
+    }
   }
   return sample.forget();
 }
diff --git a/dom/media/ogg/OggDemuxer.cpp b/dom/media/ogg/OggDemuxer.cpp
index 591a5248f..0cc484687 100644
--- a/dom/media/ogg/OggDemuxer.cpp
+++ b/dom/media/ogg/OggDemuxer.cpp
@@ -12,7 +12,6 @@
 #include "mozilla/Atomics.h"
 #include "mozilla/PodOperations.h"
 #include "mozilla/SharedThreadPool.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/TimeStamp.h"
 #include "MediaDataDemuxer.h"
 #include "nsAutoRef.h"
@@ -164,7 +163,6 @@ OggDemuxer::~OggDemuxer()
       MOZ_LOG(gMediaDemuxerLog, mozilla::LogLevel::Debug,
               ("OggDemuxer(%p)::%s: Reporting telemetry MEDIA_OGG_LOADED_IS_CHAINED=%d",
                ptr, __func__, isChained));
-      Telemetry::Accumulate(Telemetry::ID::MEDIA_OGG_LOADED_IS_CHAINED, isChained);
     });
     AbstractThread::MainThread()->Dispatch(task.forget());
   }
diff --git a/dom/media/platforms/wmf/DXVA2Manager.cpp b/dom/media/platforms/wmf/DXVA2Manager.cpp
index 0c1734c54..1226ea621 100644
--- a/dom/media/platforms/wmf/DXVA2Manager.cpp
+++ b/dom/media/platforms/wmf/DXVA2Manager.cpp
@@ -14,7 +14,6 @@
 #include "mozilla/layers/D3D11ShareHandleImage.h"
 #include "mozilla/layers/ImageBridgeChild.h"
 #include "mozilla/layers/TextureForwarder.h"
-#include "mozilla/Telemetry.h"
 #include "MediaTelemetryConstants.h"
 #include "mfapi.h"
 #include "gfxPrefs.h"
@@ -442,9 +441,6 @@ D3D9DXVA2Manager::Init(layers::KnowsCompositor* aKnowsCompositor,
   }
   mTextureClientAllocator->SetMaxPoolSize(5);
 
-  Telemetry::Accumulate(Telemetry::MEDIA_DECODER_BACKEND_USED,
-                        uint32_t(media::MediaDecoderBackend::WMFDXVA2D3D9));
-
   return S_OK;
 }
 
@@ -775,9 +771,6 @@ D3D11DXVA2Manager::Init(layers::KnowsCompositor* aKnowsCompositor,
   }
   mTextureClientAllocator->SetMaxPoolSize(5);
 
-  Telemetry::Accumulate(Telemetry::MEDIA_DECODER_BACKEND_USED,
-                        uint32_t(media::MediaDecoderBackend::WMFDXVA2D3D11));
-
   return S_OK;
 }
 
diff --git a/dom/media/platforms/wmf/WMFAudioMFTManager.cpp b/dom/media/platforms/wmf/WMFAudioMFTManager.cpp
index 69b62da51..3dacdf0aa 100644
--- a/dom/media/platforms/wmf/WMFAudioMFTManager.cpp
+++ b/dom/media/platforms/wmf/WMFAudioMFTManager.cpp
@@ -252,7 +252,6 @@ WMFAudioMFTManager::Output(int64_t aStreamOffset,
     LOG("Audio MFTDecoder returned success but null output.");
     nsCOMPtr<nsIRunnable> task = NS_NewRunnableFunction([]() -> void {
       LOG("Reporting telemetry AUDIO_MFT_OUTPUT_NULL_SAMPLES");
-      Telemetry::Accumulate(Telemetry::ID::AUDIO_MFT_OUTPUT_NULL_SAMPLES, 1);
     });
     AbstractThread::MainThread()->Dispatch(task.forget());
     return E_FAIL;
diff --git a/dom/media/platforms/wmf/WMFMediaDataDecoder.cpp b/dom/media/platforms/wmf/WMFMediaDataDecoder.cpp
index d2c13eac7..15e2e1097 100644
--- a/dom/media/platforms/wmf/WMFMediaDataDecoder.cpp
+++ b/dom/media/platforms/wmf/WMFMediaDataDecoder.cpp
@@ -8,7 +8,6 @@
 #include "VideoUtils.h"
 #include "WMFUtils.h"
 #include "nsTArray.h"
-#include "mozilla/Telemetry.h"
 
 #include "mozilla/Logging.h"
 #include "mozilla/SyncRunnable.h"
@@ -67,7 +66,7 @@ SendTelemetry(unsigned long hr)
 
   nsCOMPtr<nsIRunnable> runnable = NS_NewRunnableFunction(
     [sample] {
-      Telemetry::Accumulate(Telemetry::MEDIA_WMF_DECODE_ERROR, sample);
+      /* Telemetry STUB */
     });
   NS_DispatchToMainThread(runnable);
 }
diff --git a/dom/media/platforms/wmf/WMFVideoMFTManager.cpp b/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
index 291bc5b74..8a51f817a 100644
--- a/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
+++ b/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
@@ -128,7 +128,6 @@ WMFVideoMFTManager::~WMFVideoMFTManager()
 
   nsCOMPtr<nsIRunnable> task = NS_NewRunnableFunction([=]() -> void {
     LOG(nsPrintfCString("Reporting telemetry VIDEO_MFT_OUTPUT_NULL_SAMPLES=%d", telemetry).get());
-    Telemetry::Accumulate(Telemetry::ID::VIDEO_MFT_OUTPUT_NULL_SAMPLES, telemetry);
   });
   AbstractThread::MainThread()->Dispatch(task.forget());
 }
@@ -511,8 +510,6 @@ WMFVideoMFTManager::InitInternal(bool aForceD3D9)
     if (mStreamType == VP9 || mStreamType == VP8) {
       return false;
     }
-    Telemetry::Accumulate(Telemetry::MEDIA_DECODER_BACKEND_USED,
-                          uint32_t(media::MediaDecoderBackend::WMFSoftware));
   }
 
   mDecoder = decoder;
diff --git a/dom/media/systemservices/LoadManager.cpp b/dom/media/systemservices/LoadManager.cpp
index f0f4f83a7..34b8fc7e0 100644
--- a/dom/media/systemservices/LoadManager.cpp
+++ b/dom/media/systemservices/LoadManager.cpp
@@ -15,7 +15,6 @@
 #include "nsThreadUtils.h"
 #include "nsReadableUtils.h"
 #include "nsIObserverService.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/ArrayUtils.h"
 
 // MOZ_LOG=LoadManager:5
@@ -192,23 +191,6 @@ LoadManagerSingleton::RemoveObserver(webrtc::CPULoadStateObserver * aObserver)
     for (size_t i = 0; i < MOZ_ARRAY_LENGTH(mTimeInState); i++) {
       total += mTimeInState[i];
     }
-    // Don't include short calls; we don't have reasonable load data, and
-    // such short calls rarely reach a stable state.  Keep relatively
-    // short calls separate from longer ones
-    bool log = total > 5*PR_MSEC_PER_SEC;
-    bool small = log && total < 30*PR_MSEC_PER_SEC;
-    if (log) {
-      // Note: We don't care about rounding here; thus total may be < 100
-      Telemetry::Accumulate(small ? Telemetry::WEBRTC_LOAD_STATE_RELAXED_SHORT :
-                            Telemetry::WEBRTC_LOAD_STATE_RELAXED,
-                            (uint32_t) (mTimeInState[webrtc::CPULoadState::kLoadRelaxed]/total * 100));
-      Telemetry::Accumulate(small ? Telemetry::WEBRTC_LOAD_STATE_NORMAL_SHORT :
-                            Telemetry::WEBRTC_LOAD_STATE_NORMAL,
-                            (uint32_t) (mTimeInState[webrtc::CPULoadState::kLoadNormal]/total * 100));
-      Telemetry::Accumulate(small ? Telemetry::WEBRTC_LOAD_STATE_STRESSED_SHORT :
-                            Telemetry::WEBRTC_LOAD_STATE_STRESSED,
-                            (uint32_t) (mTimeInState[webrtc::CPULoadState::kLoadStressed]/total * 100));
-    }
     for (auto &in_state : mTimeInState) {
       in_state = 0;
     }
diff --git a/dom/media/webaudio/MediaBufferDecoder.cpp b/dom/media/webaudio/MediaBufferDecoder.cpp
index e9f1d5a47..2ee11eacd 100644
--- a/dom/media/webaudio/MediaBufferDecoder.cpp
+++ b/dom/media/webaudio/MediaBufferDecoder.cpp
@@ -23,7 +23,6 @@
 #include "VideoUtils.h"
 #include "WebAudioUtils.h"
 #include "mozilla/dom/Promise.h"
-#include "mozilla/Telemetry.h"
 #include "nsPrintfCString.h"
 #include "GMPService.h"
 
@@ -302,7 +301,6 @@ MediaDecodeTask::OnMetadataRead(MetadataHolder* aMetadata)
     MOZ_LOG(gMediaDecoderLog,
             LogLevel::Debug,
             ("Telemetry (WebAudio) MEDIA_CODEC_USED= '%s'", codec.get()));
-    Telemetry::Accumulate(Telemetry::ID::MEDIA_CODEC_USED, codec);
   });
   AbstractThread::MainThread()->Dispatch(task.forget());
 
diff --git a/dom/notification/Notification.cpp b/dom/notification/Notification.cpp
index 1dd5724e4..71c4916b9 100644
--- a/dom/notification/Notification.cpp
+++ b/dom/notification/Notification.cpp
@@ -642,8 +642,6 @@ NotificationPermissionRequest::ResolvePromise()
     mCallback->Call(mPermission, error);
     rv = error.StealNSResult();
   }
-  Telemetry::Accumulate(
-    Telemetry::WEB_NOTIFICATION_REQUEST_PERMISSION_CALLBACK, !!mCallback);
   mPromise->MaybeResolve(mPermission);
   return rv;
 }
@@ -750,11 +748,6 @@ NotificationTelemetryService::RecordPermissions()
     if (!GetNotificationPermission(supportsPermission, &capability)) {
       continue;
     }
-    if (capability == nsIPermissionManager::DENY_ACTION) {
-      Telemetry::Accumulate(Telemetry::WEB_NOTIFICATION_PERMISSIONS, 0);
-    } else if (capability == nsIPermissionManager::ALLOW_ACTION) {
-      Telemetry::Accumulate(Telemetry::WEB_NOTIFICATION_PERMISSIONS, 1);
-    }
   }
 }
 
@@ -800,9 +793,6 @@ NotificationTelemetryService::RecordDNDSupported()
   if (NS_FAILED(rv)) {
     return;
   }
-
-  Telemetry::Accumulate(
-    Telemetry::ALERTS_SERVICE_DND_SUPPORTED_FLAG, true);
 }
 
 nsresult
@@ -819,7 +809,6 @@ NotificationTelemetryService::RecordSender(nsIPrincipal* aPrincipal)
   }
   if (!mOrigins.Contains(origin)) {
     mOrigins.PutEntry(origin);
-    Telemetry::Accumulate(Telemetry::WEB_NOTIFICATION_SENDERS, 1);
   }
   return NS_OK;
 }
@@ -829,21 +818,7 @@ NotificationTelemetryService::Observe(nsISupports* aSubject,
                                       const char* aTopic,
                                       const char16_t* aData)
 {
-  uint32_t capability;
-  if (strcmp("perm-changed", aTopic) ||
-      !NS_strcmp(u"cleared", aData) ||
-      !GetNotificationPermission(aSubject, &capability)) {
-    return NS_OK;
-  }
-  if (!NS_strcmp(u"deleted", aData)) {
-    if (capability == nsIPermissionManager::DENY_ACTION) {
-      Telemetry::Accumulate(
-        Telemetry::WEB_NOTIFICATION_PERMISSION_REMOVED, 0);
-    } else if (capability == nsIPermissionManager::ALLOW_ACTION) {
-      Telemetry::Accumulate(
-        Telemetry::WEB_NOTIFICATION_PERMISSION_REMOVED, 1);
-    }
-  }
+  /* STUB */
   return NS_OK;
 }
 
@@ -1407,7 +1382,6 @@ NotificationObserver::Observe(nsISupports* aSubject, const char* aTopic,
   AssertIsOnMainThread();
 
   if (!strcmp("alertdisablecallback", aTopic)) {
-    Telemetry::Accumulate(Telemetry::WEB_NOTIFICATION_MENU, 1);
     if (XRE_IsParentProcess()) {
       return Notification::RemovePermission(mPrincipal);
     }
@@ -1417,10 +1391,7 @@ NotificationObserver::Observe(nsISupports* aSubject, const char* aTopic,
     ContentChild::GetSingleton()->SendDisableNotifications(
       IPC::Principal(mPrincipal));
     return NS_OK;
-  } else if (!strcmp("alertclickcallback", aTopic)) {
-    Telemetry::Accumulate(Telemetry::WEB_NOTIFICATION_CLICKED, 1);
   } else if (!strcmp("alertsettingscallback", aTopic)) {
-    Telemetry::Accumulate(Telemetry::WEB_NOTIFICATION_MENU, 2);
     if (XRE_IsParentProcess()) {
       return Notification::OpenSettings(mPrincipal);
     }
@@ -1433,21 +1404,7 @@ NotificationObserver::Observe(nsISupports* aSubject, const char* aTopic,
              !strcmp("alertfinished", aTopic)) {
     RefPtr<NotificationTelemetryService> telemetry =
       NotificationTelemetryService::GetInstance();
-    if (telemetry) {
-      // Record whether "do not disturb" is supported after the first
-      // notification, to account for falling back to XUL alerts.
-      telemetry->RecordDNDSupported();
-      if (!mInPrivateBrowsing) {
-        // Ignore senders in private windows.
-        Unused << NS_WARN_IF(NS_FAILED(telemetry->RecordSender(mPrincipal)));
-      }
-    }
     Unused << NS_WARN_IF(NS_FAILED(AdjustPushQuota(aTopic)));
-
-    if (!strcmp("alertshow", aTopic)) {
-      // Record notifications actually shown (e.g. don't count if DND is on).
-      Telemetry::Accumulate(Telemetry::WEB_NOTIFICATION_SHOWN, 1);
-    }
   }
 
   return mObserver->Observe(aSubject, aTopic, aData);
diff --git a/dom/plugins/base/nsPluginHost.cpp b/dom/plugins/base/nsPluginHost.cpp
index 916bdea0f..c3de136d0 100644
--- a/dom/plugins/base/nsPluginHost.cpp
+++ b/dom/plugins/base/nsPluginHost.cpp
@@ -2148,11 +2148,7 @@ nsresult nsPluginHost::ScanPluginsDirectory(nsIFile *pluginsDir,
       nsPluginInfo info;
       memset(&info, 0, sizeof(info));
       nsresult res;
-      // Opening a block for the telemetry AutoTimer
-      {
-        Telemetry::AutoTimer<Telemetry::PLUGIN_LOAD_METADATA> telemetry;
-        res = pluginFile.GetPluginInfo(info, &library);
-      }
+      res = pluginFile.GetPluginInfo(info, &library);
       // if we don't have mime type don't proceed, this is not a plugin
       if (NS_FAILED(res) || !info.fMimeTypeArray) {
         RefPtr<nsInvalidPluginTag> invalidTag = new nsInvalidPluginTag(filePath.get(),
@@ -2410,8 +2406,6 @@ nsPluginHost::FindPluginsInContent(bool aCreatePluginList, bool* aPluginsChanged
 // This is needed in ReloadPlugins to prevent possible recursive reloads
 nsresult nsPluginHost::FindPlugins(bool aCreatePluginList, bool * aPluginsChanged)
 {
-  Telemetry::AutoTimer<Telemetry::FIND_PLUGINS> telemetry;
-
   NS_ENSURE_ARG_POINTER(aPluginsChanged);
 
   *aPluginsChanged = false;
@@ -3412,7 +3406,6 @@ nsPluginHost::StopPluginInstance(nsNPAPIPluginInstance* aInstance)
     return NS_OK;
   }
 
-  Telemetry::AutoTimer<Telemetry::PLUGIN_SHUTDOWN_MS> timer;
   aInstance->Stop();
 
   // if the instance does not want to be 'cached' just remove it
diff --git a/dom/plugins/ipc/PluginAsyncSurrogate.cpp b/dom/plugins/ipc/PluginAsyncSurrogate.cpp
index da07116cc..3fe4c7168 100644
--- a/dom/plugins/ipc/PluginAsyncSurrogate.cpp
+++ b/dom/plugins/ipc/PluginAsyncSurrogate.cpp
@@ -504,8 +504,6 @@ PluginAsyncSurrogate::WaitForInit()
   if (mAcceptCalls) {
     return true;
   }
-  Telemetry::AutoTimer<Telemetry::BLOCKED_ON_PLUGINASYNCSURROGATE_WAITFORINIT_MS>
-    timer(mParent->GetHistogramKey());
   bool result = false;
   MOZ_ASSERT(mParent);
   if (mParent->IsChrome()) {
diff --git a/dom/plugins/ipc/PluginHangUIParent.cpp b/dom/plugins/ipc/PluginHangUIParent.cpp
index 5114f2e9a..908182a22 100644
--- a/dom/plugins/ipc/PluginHangUIParent.cpp
+++ b/dom/plugins/ipc/PluginHangUIParent.cpp
@@ -8,7 +8,6 @@
 
 #include "PluginHangUIParent.h"
 
-#include "mozilla/Telemetry.h"
 #include "mozilla/ipc/ProtocolUtils.h"
 #include "mozilla/plugins/PluginModuleParent.h"
 
@@ -48,14 +47,6 @@ public:
   NS_IMETHOD
   Run() override
   {
-    mozilla::Telemetry::Accumulate(
-              mozilla::Telemetry::PLUGIN_HANG_UI_USER_RESPONSE, mResponseCode);
-    mozilla::Telemetry::Accumulate(
-              mozilla::Telemetry::PLUGIN_HANG_UI_DONT_ASK, mDontAskCode);
-    mozilla::Telemetry::Accumulate(
-              mozilla::Telemetry::PLUGIN_HANG_UI_RESPONSE_TIME, mResponseTimeMs);
-    mozilla::Telemetry::Accumulate(
-              mozilla::Telemetry::PLUGIN_HANG_TIME, mTimeoutMs + mResponseTimeMs);
     return NS_OK;
   }
 
diff --git a/dom/plugins/ipc/PluginInstanceParent.cpp b/dom/plugins/ipc/PluginInstanceParent.cpp
index 02f0641f7..bdd15ca99 100644
--- a/dom/plugins/ipc/PluginInstanceParent.cpp
+++ b/dom/plugins/ipc/PluginInstanceParent.cpp
@@ -9,7 +9,6 @@
 
 #include "mozilla/BasicEvents.h"
 #include "mozilla/Preferences.h"
-#include "mozilla/Telemetry.h"
 #include "PluginInstanceParent.h"
 #include "BrowserStreamParent.h"
 #include "PluginAsyncSurrogate.h"
@@ -206,12 +205,8 @@ NPError
 PluginInstanceParent::Destroy()
 {
     NPError retval;
-    {   // Scope for timer
-        Telemetry::AutoTimer<Telemetry::BLOCKED_ON_PLUGIN_INSTANCE_DESTROY_MS>
-            timer(Module()->GetHistogramKey());
-        if (!CallNPP_Destroy(&retval)) {
-            retval = NPERR_GENERIC_ERROR;
-        }
+    if (!CallNPP_Destroy(&retval)) {
+        retval = NPERR_GENERIC_ERROR;
     }
 
 #if defined(OS_WIN)
@@ -1786,9 +1781,6 @@ PluginInstanceParent::NPP_NewStream(NPMIMEType type, NPStream* stream,
         return NPERR_GENERIC_ERROR;
     }
 
-    Telemetry::AutoTimer<Telemetry::BLOCKED_ON_PLUGIN_STREAM_INIT_MS>
-        timer(Module()->GetHistogramKey());
-
     NPError err = NPERR_NO_ERROR;
     if (mParent->IsStartingAsync()) {
         MOZ_ASSERT(mSurrogate);
@@ -2504,6 +2496,5 @@ PluginInstanceParent::RecordDrawingModel()
     }
     MOZ_ASSERT(mode >= 0);
 
-    Telemetry::Accumulate(Telemetry::PLUGIN_DRAWING_MODEL, mode);
     mLastRecordedDrawingModel = mode;
 }
diff --git a/dom/plugins/ipc/PluginModuleParent.cpp b/dom/plugins/ipc/PluginModuleParent.cpp
index 2489baf16..300c4f621 100755
--- a/dom/plugins/ipc/PluginModuleParent.cpp
+++ b/dom/plugins/ipc/PluginModuleParent.cpp
@@ -20,7 +20,6 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/ProcessHangMonitor.h"
 #include "mozilla/Services.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/Unused.h"
 #include "nsAutoPtr.h"
 #include "nsCRT.h"
@@ -1172,11 +1171,6 @@ PluginModuleParent::GetRunID(uint32_t* aRunID)
 void
 PluginModuleChromeParent::ActorDestroy(ActorDestroyReason why)
 {
-    if (why == AbnormalShutdown) {
-        Telemetry::Accumulate(Telemetry::SUBPROCESS_ABNORMAL_ABORT,
-                              NS_LITERAL_CSTRING("plugin"), 1);
-    }
-
     // We can't broadcast settings changes anymore.
     UnregisterSettingsCallbacks();
 
@@ -2203,12 +2197,8 @@ public:
 void
 PluginModuleParent::AccumulateModuleInitBlockedTime()
 {
-    if (mPluginName.IsEmpty()) {
-        GetPluginDetails();
-    }
-    Telemetry::Accumulate(Telemetry::BLOCKED_ON_PLUGIN_MODULE_INIT_MS,
-                          GetHistogramKey(),
-                          static_cast<uint32_t>(mTimeBlocked.ToMilliseconds()));
+    // XXX: mTimeBlocked can probably go if not used for anything besides
+    // telemetry.
     mTimeBlocked = TimeDuration();
 }
 
@@ -2294,27 +2284,23 @@ PluginModuleParent::NPP_NewInternal(NPMIMEType pluginType, NPP instance,
         return NS_ERROR_FAILURE;
     }
 
-    {   // Scope for timer
-        Telemetry::AutoTimer<Telemetry::BLOCKED_ON_PLUGIN_INSTANCE_INIT_MS>
-            timer(GetHistogramKey());
-        if (mIsStartingAsync) {
-            MOZ_ASSERT(surrogate);
-            surrogate->AsyncCallDeparting();
-            if (!SendAsyncNPP_New(parentInstance)) {
+    if (mIsStartingAsync) {
+        MOZ_ASSERT(surrogate);
+        surrogate->AsyncCallDeparting();
+        if (!SendAsyncNPP_New(parentInstance)) {
+            *error = NPERR_GENERIC_ERROR;
+            return NS_ERROR_FAILURE;
+        }
+        *error = NPERR_NO_ERROR;
+    } else {
+        if (!CallSyncNPP_New(parentInstance, error)) {
+            // if IPC is down, we'll get an immediate "failed" return, but
+            // without *error being set.  So make sure that the error
+            // condition is signaled to nsNPAPIPluginInstance
+            if (NPERR_NO_ERROR == *error) {
                 *error = NPERR_GENERIC_ERROR;
-                return NS_ERROR_FAILURE;
-            }
-            *error = NPERR_NO_ERROR;
-        } else {
-            if (!CallSyncNPP_New(parentInstance, error)) {
-                // if IPC is down, we'll get an immediate "failed" return, but
-                // without *error being set.  So make sure that the error
-                // condition is signaled to nsNPAPIPluginInstance
-                if (NPERR_NO_ERROR == *error) {
-                    *error = NPERR_GENERIC_ERROR;
-                }
-                return NS_ERROR_FAILURE;
             }
+            return NS_ERROR_FAILURE;
         }
     }
 
diff --git a/dom/presentation/provider/PresentationControlService.js b/dom/presentation/provider/PresentationControlService.js
index fe61d26d6..e9f92247f 100644
--- a/dom/presentation/provider/PresentationControlService.js
+++ b/dom/presentation/provider/PresentationControlService.js
@@ -100,7 +100,6 @@ PresentationControlService.prototype = {
 
       if (aCert) {
         this._serverSocket.serverCert = aCert;
-        this._serverSocket.setSessionCache(false);
         this._serverSocket.setSessionTickets(false);
         let requestCert = Ci.nsITLSServerSocket.REQUEST_NEVER;
         this._serverSocket.setRequestClientCertificate(requestCert);
diff --git a/dom/security/nsMixedContentBlocker.cpp b/dom/security/nsMixedContentBlocker.cpp
index c03628da0..5f41f414d 100644
--- a/dom/security/nsMixedContentBlocker.cpp
+++ b/dom/security/nsMixedContentBlocker.cpp
@@ -983,44 +983,5 @@ enum MixedContentHSTSState {
 void
 nsMixedContentBlocker::AccumulateMixedContentHSTS(nsIURI* aURI, bool aActive)
 {
-  // This method must only be called in the parent, because
-  // nsSiteSecurityService is only available in the parent
-  if (!XRE_IsParentProcess()) {
-    MOZ_ASSERT(false);
-    return;
-  }
-
-  bool hsts;
-  nsresult rv;
-  nsCOMPtr<nsISiteSecurityService> sss = do_GetService(NS_SSSERVICE_CONTRACTID, &rv);
-  if (NS_FAILED(rv)) {
-    return;
-  }
-  rv = sss->IsSecureURI(nsISiteSecurityService::HEADER_HSTS, aURI, 0, nullptr, &hsts);
-  if (NS_FAILED(rv)) {
-    return;
-  }
-
-  // states: would upgrade, hsts info cached
-  // active, passive
-  //
-  if (!aActive) {
-    if (!hsts) {
-      Telemetry::Accumulate(Telemetry::MIXED_CONTENT_HSTS,
-                            MCB_HSTS_PASSIVE_NO_HSTS);
-    }
-    else {
-      Telemetry::Accumulate(Telemetry::MIXED_CONTENT_HSTS,
-                            MCB_HSTS_PASSIVE_WITH_HSTS);
-    }
-  } else {
-    if (!hsts) {
-      Telemetry::Accumulate(Telemetry::MIXED_CONTENT_HSTS,
-                            MCB_HSTS_ACTIVE_NO_HSTS);
-    }
-    else {
-      Telemetry::Accumulate(Telemetry::MIXED_CONTENT_HSTS,
-                            MCB_HSTS_ACTIVE_WITH_HSTS);
-    }
-  }
+/* STUB */
 }
\ No newline at end of file
diff --git a/dom/storage/DOMStorageCache.cpp b/dom/storage/DOMStorageCache.cpp
index 811f79fd3..a6aa17424 100644
--- a/dom/storage/DOMStorageCache.cpp
+++ b/dom/storage/DOMStorageCache.cpp
@@ -309,7 +309,7 @@ public:
   explicit TelemetryAutoTimer(Telemetry::ID aId)
     : id(aId), start(TimeStamp::Now()) {}
   ~TelemetryAutoTimer()
-    { Telemetry::AccumulateDelta_impl<Telemetry::Millisecond>::compute(id, start); }
+    { /* STUB */ }
 private:
   Telemetry::ID id;
   const TimeStamp start;
@@ -329,9 +329,6 @@ DOMStorageCache::WaitForPreload(Telemetry::ID aTelemetryID)
   // Telemetry of rates of pending preloads
   if (!mPreloadTelemetryRecorded) {
     mPreloadTelemetryRecorded = true;
-    Telemetry::Accumulate(
-      Telemetry::LOCALDOMSTORAGE_PRELOAD_PENDING_ON_FIRST_ACCESS,
-      !loaded);
   }
 
   if (loaded) {
diff --git a/dom/storage/DOMStorageDBThread.cpp b/dom/storage/DOMStorageDBThread.cpp
index 183be5c5c..f86dbad9c 100644
--- a/dom/storage/DOMStorageDBThread.cpp
+++ b/dom/storage/DOMStorageDBThread.cpp
@@ -163,8 +163,6 @@ DOMStorageDBThread::Shutdown()
     return NS_ERROR_NOT_INITIALIZED;
   }
 
-  Telemetry::AutoTimer<Telemetry::LOCALDOMSTORAGE_SHUTDOWN_DATABASE_MS> timer;
-
   {
     MonitorAutoLock monitor(mThreadObserver->GetMonitor());
 
diff --git a/dom/system/mac/CoreLocationLocationProvider.mm b/dom/system/mac/CoreLocationLocationProvider.mm
index b39582a9e..7a3feba97 100644
--- a/dom/system/mac/CoreLocationLocationProvider.mm
+++ b/dom/system/mac/CoreLocationLocationProvider.mm
@@ -13,7 +13,6 @@
 #include "CoreLocationLocationProvider.h"
 #include "nsCocoaFeatures.h"
 #include "prtime.h"
-#include "mozilla/Telemetry.h"
 #include "MLSFallback.h"
 
 #include <CoreLocation/CLError.h>
@@ -103,7 +102,6 @@ static const CLLocationAccuracy kDEFAULT_ACCURACY = kCLLocationAccuracyNearestTe
                       PR_Now() / PR_USEC_PER_MSEC);
 
   mProvider->Update(geoPosition);
-  Telemetry::Accumulate(Telemetry::GEOLOCATION_OSX_SOURCE_IS_MLS, false);
 }
 @end
 
@@ -127,7 +125,6 @@ CoreLocationLocationProvider::MLSUpdate::Update(nsIDOMGeoPosition *position)
     return NS_ERROR_FAILURE;
   }
   mParentLocationProvider.Update(position);
-  Telemetry::Accumulate(Telemetry::GEOLOCATION_OSX_SOURCE_IS_MLS, true);
   return NS_OK;
 }
 NS_IMETHODIMP
diff --git a/dom/system/windows/WindowsLocationProvider.cpp b/dom/system/windows/WindowsLocationProvider.cpp
index fa7f8d8be..9da7bcc30 100644
--- a/dom/system/windows/WindowsLocationProvider.cpp
+++ b/dom/system/windows/WindowsLocationProvider.cpp
@@ -10,7 +10,6 @@
 #include "nsComponentManagerUtils.h"
 #include "prtime.h"
 #include "MLSFallback.h"
-#include "mozilla/Telemetry.h"
 
 namespace mozilla {
 namespace dom {
@@ -34,7 +33,6 @@ WindowsLocationProvider::MLSUpdate::Update(nsIDOMGeoPosition *aPosition)
   if (!coords) {
     return NS_ERROR_FAILURE;
   }
-  Telemetry::Accumulate(Telemetry::GEOLOCATION_WIN8_SOURCE_IS_MLS, true);
   return mCallback->Update(aPosition);
 }
 NS_IMETHODIMP
@@ -176,8 +174,6 @@ LocationEvent::OnLocationChanged(REFIID aReportType,
                       PR_Now() / PR_USEC_PER_MSEC);
   mCallback->Update(position);
 
-  Telemetry::Accumulate(Telemetry::GEOLOCATION_WIN8_SOURCE_IS_MLS, false);
-
   return S_OK;
 }
 
diff --git a/dom/webidl/DataTransfer.webidl b/dom/webidl/DataTransfer.webidl
index 206d80804..dd44e1ddc 100644
--- a/dom/webidl/DataTransfer.webidl
+++ b/dom/webidl/DataTransfer.webidl
@@ -7,7 +7,7 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-datatransfer-interface
  */
 
-[ChromeConstructor(DOMString eventType, boolean isExternal)]
+[Constructor]
 interface DataTransfer {
            attribute DOMString dropEffect;
            attribute DOMString effectAllowed;
diff --git a/dom/webidl/HTMLDocument.webidl b/dom/webidl/HTMLDocument.webidl
index 42f6d98f7..ffb61ccdd 100644
--- a/dom/webidl/HTMLDocument.webidl
+++ b/dom/webidl/HTMLDocument.webidl
@@ -7,7 +7,7 @@
 [OverrideBuiltins]
 interface HTMLDocument : Document {
            [SetterThrows]
-           attribute DOMString? domain;
+           attribute DOMString domain;
            [Throws]
            attribute DOMString cookie;
   // DOM tree accessors
diff --git a/dom/webidl/WebGLRenderingContext.webidl b/dom/webidl/WebGLRenderingContext.webidl
index dd0e6ff69..323d23421 100644
--- a/dom/webidl/WebGLRenderingContext.webidl
+++ b/dom/webidl/WebGLRenderingContext.webidl
@@ -1046,3 +1046,12 @@ interface EXT_disjoint_timer_query {
     any getQueryEXT(GLenum target, GLenum pname);
     any getQueryObjectEXT(WebGLQuery query, GLenum pname);
 };
+
+[NoInterfaceObject]
+interface MOZ_debug_get {
+    const GLenum EXTENSIONS = 0x1F03;
+    const GLenum WSI_INFO   = 0x10000;
+
+    [Throws]
+    any getParameter(GLenum pname);
+};
diff --git a/dom/workers/RuntimeService.cpp b/dom/workers/RuntimeService.cpp
index e1910536f..1f49e16dd 100644
--- a/dom/workers/RuntimeService.cpp
+++ b/dom/workers/RuntimeService.cpp
@@ -30,7 +30,6 @@
 #include "mozilla/AsyncEventDispatcher.h"
 #include "mozilla/Atomics.h"
 #include "mozilla/CycleCollectedJSContext.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/dom/asmjscache/AsmJSCache.h"
 #include "mozilla/dom/AtomList.h"
@@ -1534,7 +1533,6 @@ RuntimeService::RegisterWorker(WorkerPrivate* aWorkerPrivate)
   const bool isDedicatedWorker = aWorkerPrivate->IsDedicatedWorker();
   if (isServiceWorker) {
     AssertIsOnMainThread();
-    Telemetry::Accumulate(Telemetry::SERVICE_WORKER_SPAWN_ATTEMPTS, 1);
   }
 
   nsCString sharedWorkerScriptSpec;
@@ -1586,14 +1584,6 @@ RuntimeService::RegisterWorker(WorkerPrivate* aWorkerPrivate)
       // Worker spawn gets queued due to hitting max workers per domain
       // limit so let's log a warning.
       WorkerPrivate::ReportErrorToConsole("HittingMaxWorkersPerDomain2");
-
-      if (isServiceWorker) {
-        Telemetry::Accumulate(Telemetry::SERVICE_WORKER_SPAWN_GETS_QUEUED, 1);
-      } else if (isSharedWorker) {
-        Telemetry::Accumulate(Telemetry::SHARED_WORKER_SPAWN_GETS_QUEUED, 1);
-      } else if (isDedicatedWorker) {
-        Telemetry::Accumulate(Telemetry::DEDICATED_WORKER_SPAWN_GETS_QUEUED, 1);
-      }
     }
     else if (parent) {
       domainInfo->mChildWorkerCount++;
@@ -1669,7 +1659,6 @@ RuntimeService::RegisterWorker(WorkerPrivate* aWorkerPrivate)
 
   if (isServiceWorker) {
     AssertIsOnMainThread();
-    Telemetry::Accumulate(Telemetry::SERVICE_WORKER_WAS_SPAWNED, 1);
   }
   return true;
 }
@@ -1766,8 +1755,6 @@ RuntimeService::UnregisterWorker(WorkerPrivate* aWorkerPrivate)
 
   if (aWorkerPrivate->IsServiceWorker()) {
     AssertIsOnMainThread();
-    Telemetry::AccumulateTimeDelta(Telemetry::SERVICE_WORKER_LIFE_TIME,
-                                   aWorkerPrivate->CreationTimeStamp());
   }
 
   if (aWorkerPrivate->IsSharedWorker() ||
diff --git a/dom/workers/ServiceWorkerManager.cpp b/dom/workers/ServiceWorkerManager.cpp
index a66df0731..a8f191f2e 100644
--- a/dom/workers/ServiceWorkerManager.cpp
+++ b/dom/workers/ServiceWorkerManager.cpp
@@ -33,7 +33,6 @@
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/ErrorNames.h"
 #include "mozilla/LoadContext.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/dom/DOMError.h"
@@ -676,7 +675,6 @@ ServiceWorkerManager::Register(mozIDOMWindow* aWindow,
   queue->ScheduleJob(job);
 
   AssertIsOnMainThread();
-  Telemetry::Accumulate(Telemetry::SERVICE_WORKER_REGISTRATIONS, 1);
 
   promise.forget(aPromise);
   return NS_OK;
@@ -2180,7 +2178,6 @@ ServiceWorkerManager::StartControllingADocument(ServiceWorkerRegistrationInfo* a
   if (!aDocumentId.IsEmpty()) {
     aDoc->SetId(aDocumentId);
   }
-  Telemetry::Accumulate(Telemetry::SERVICE_WORKER_CONTROLLED_DOCUMENTS, 1);
 }
 
 void
diff --git a/dom/workers/ServiceWorkerRegistrar.cpp b/dom/workers/ServiceWorkerRegistrar.cpp
index a4757ea54..7df129c2b 100644
--- a/dom/workers/ServiceWorkerRegistrar.cpp
+++ b/dom/workers/ServiceWorkerRegistrar.cpp
@@ -135,9 +135,6 @@ ServiceWorkerRegistrar::GetRegistrations(
 
   if (firstTime) {
     firstTime = false;
-    Telemetry::AccumulateTimeDelta(
-      Telemetry::SERVICE_WORKER_REGISTRATION_LOADING,
-      startTime);
   }
 }
 
diff --git a/dom/workers/ServiceWorkerUpdateJob.cpp b/dom/workers/ServiceWorkerUpdateJob.cpp
index 614fe4de5..69877dfe4 100644
--- a/dom/workers/ServiceWorkerUpdateJob.cpp
+++ b/dom/workers/ServiceWorkerUpdateJob.cpp
@@ -408,8 +408,6 @@ ServiceWorkerUpdateJob::ComparisonResult(nsresult aStatus,
     return;
   }
 
-  Telemetry::Accumulate(Telemetry::SERVICE_WORKER_UPDATED, 1);
-
   // Begin step 7 of the Update algorithm to evaluate the new script.
 
   RefPtr<ServiceWorkerInfo> sw =
diff --git a/dom/workers/SharedWorker.cpp b/dom/workers/SharedWorker.cpp
index b0eed2def..99bb50339 100644
--- a/dom/workers/SharedWorker.cpp
+++ b/dom/workers/SharedWorker.cpp
@@ -12,7 +12,6 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/dom/MessagePort.h"
 #include "mozilla/dom/SharedWorkerBinding.h"
-#include "mozilla/Telemetry.h"
 #include "nsContentUtils.h"
 #include "nsIClassInfoImpl.h"
 #include "nsIDOMEvent.h"
@@ -73,8 +72,6 @@ SharedWorker::Constructor(const GlobalObject& aGlobal, JSContext* aCx,
     return nullptr;
   }
 
-  Telemetry::Accumulate(Telemetry::SHARED_WORKER_COUNT, 1);
-
   return sharedWorker.forget();
 }
 
diff --git a/dom/workers/WorkerRunnable.cpp b/dom/workers/WorkerRunnable.cpp
index 6bbe40f66..9e6d4cfb8 100644
--- a/dom/workers/WorkerRunnable.cpp
+++ b/dom/workers/WorkerRunnable.cpp
@@ -15,7 +15,6 @@
 #include "mozilla/DebugOnly.h"
 #include "mozilla/ErrorResult.h"
 #include "mozilla/dom/ScriptSettings.h"
-#include "mozilla/Telemetry.h"
 
 #include "js/RootingAPI.h"
 #include "js/Value.h"
@@ -572,8 +571,6 @@ WorkerMainThreadRunnable::Dispatch(Status aFailStatus, ErrorResult& aRv)
 {
   mWorkerPrivate->AssertIsOnWorkerThread();
 
-  TimeStamp startTime = TimeStamp::NowLoRes();
-
   AutoSyncLoopHolder syncLoop(mWorkerPrivate, aFailStatus);
 
   mSyncLoopTarget = syncLoop.GetEventTarget();
@@ -590,11 +587,6 @@ WorkerMainThreadRunnable::Dispatch(Status aFailStatus, ErrorResult& aRv)
   if (!syncLoop.Run()) {
     aRv.ThrowUncatchableException();
   }
-
-  Telemetry::Accumulate(Telemetry::SYNC_WORKER_OPERATION, mTelemetryKey,
-                        static_cast<uint32_t>((TimeStamp::NowLoRes() - startTime)
-                                                .ToMilliseconds()));
-  Unused << startTime; // Shut the compiler up.
 }
 
 NS_IMETHODIMP
diff --git a/dom/xhr/XMLHttpRequestMainThread.cpp b/dom/xhr/XMLHttpRequestMainThread.cpp
index 4fd34a993..613008ad5 100644
--- a/dom/xhr/XMLHttpRequestMainThread.cpp
+++ b/dom/xhr/XMLHttpRequestMainThread.cpp
@@ -757,15 +757,6 @@ XMLHttpRequestMainThread::SetResponseType(XMLHttpRequestResponseType aResponseTy
     return;
   }
 
-  // We want to get rid of this moz-only types. Bug 1335365.
-  if (aResponseType == XMLHttpRequestResponseType::Moz_blob) {
-    Telemetry::Accumulate(Telemetry::MOZ_BLOB_IN_XHR, 1);
-  } else if (aResponseType == XMLHttpRequestResponseType::Moz_chunked_text) {
-    Telemetry::Accumulate(Telemetry::MOZ_CHUNKED_TEXT_IN_XHR, 1);
-  } else if (aResponseType == XMLHttpRequestResponseType::Moz_chunked_arraybuffer) {
-    Telemetry::Accumulate(Telemetry::MOZ_CHUNKED_ARRAYBUFFER_IN_XHR, 1);
-  }
-
   // Set the responseType attribute's value to the given value.
   mResponseType = aResponseType;
 }
@@ -1521,8 +1512,6 @@ XMLHttpRequestMainThread::Open(const nsACString& aMethod,
     GetOwner()->GetExtantDoc()->WarnOnceAbout(nsIDocument::eSyncXMLHttpRequest);
   }
 
-  Telemetry::Accumulate(Telemetry::XMLHTTPREQUEST_ASYNC_OR_SYNC, aAsync ? 0 : 1);
-
   // Step 1
   nsCOMPtr<nsIDocument> responsibleDocument = GetDocumentIfCurrent();
   if (!responsibleDocument) {
diff --git a/dom/xhr/XMLHttpRequestWorker.cpp b/dom/xhr/XMLHttpRequestWorker.cpp
index c9e892f26..2af61bd7d 100644
--- a/dom/xhr/XMLHttpRequestWorker.cpp
+++ b/dom/xhr/XMLHttpRequestWorker.cpp
@@ -1588,8 +1588,6 @@ XMLHttpRequestWorker::Construct(const GlobalObject& aGlobal,
   WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(cx);
   MOZ_ASSERT(workerPrivate);
 
-  Telemetry::Accumulate(Telemetry::XHR_IN_WORKER, 1);
-
   RefPtr<XMLHttpRequestWorker> xhr = new XMLHttpRequestWorker(workerPrivate);
 
   if (workerPrivate->XHRParamsAllowed()) {
diff --git a/dom/xul/nsXULPrototypeCache.cpp b/dom/xul/nsXULPrototypeCache.cpp
index 84a201d59..2c3454860 100644
--- a/dom/xul/nsXULPrototypeCache.cpp
+++ b/dom/xul/nsXULPrototypeCache.cpp
@@ -45,12 +45,6 @@ UpdategDisableXULCache()
     // Get the value of "nglayout.debug.disable_xul_cache" preference
     gDisableXULCache =
         Preferences::GetBool(kDisableXULCachePref, gDisableXULCache);
-
-    // Sets the flag if the XUL cache is disabled
-    if (gDisableXULCache) {
-        Telemetry::Accumulate(Telemetry::XUL_CACHE_DISABLED, true);
-    }
-
 }
 
 static void