Add m-esr52 at 52.6.0

1 files changed, 1000 insertions, 0 deletions

diff --git a/layout/style/nsLayoutStylesheetCache.cpp b/layout/style/nsLayoutStylesheetCache.cpp
new file mode 100644
index 000000000..f8aea5541
--- /dev/null
+++ b/layout/style/nsLayoutStylesheetCache.cpp
@@ -0,0 +1,1000 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "nsLayoutStylesheetCache.h"
+
+#include "nsAppDirectoryServiceDefs.h"
+#include "mozilla/StyleSheetInlines.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/StyleSheet.h"
+#include "mozilla/StyleSheetInlines.h"
+#include "mozilla/css/Loader.h"
+#include "mozilla/dom/SRIMetadata.h"
+#include "nsIConsoleService.h"
+#include "nsIFile.h"
+#include "nsNetUtil.h"
+#include "nsIObserverService.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIXULRuntime.h"
+#include "nsPrintfCString.h"
+#include "nsXULAppAPI.h"
+
+// Includes for the crash report annotation in ErrorLoadingSheet.
+#ifdef MOZ_CRASHREPORTER
+#include "mozilla/Omnijar.h"
+#include "nsDirectoryService.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsExceptionHandler.h"
+#include "nsIChromeRegistry.h"
+#include "nsISimpleEnumerator.h"
+#include "nsISubstitutingProtocolHandler.h"
+#include "zlib.h"
+#include "nsZipArchive.h"
+#endif
+
+using namespace mozilla;
+using namespace mozilla::css;
+
+static bool sNumberControlEnabled;
+
+#define NUMBER_CONTROL_PREF "dom.forms.number"
+
+NS_IMPL_ISUPPORTS(
+  nsLayoutStylesheetCache, nsIObserver, nsIMemoryReporter)
+
+nsresult
+nsLayoutStylesheetCache::Observe(nsISupports* aSubject,
+                            const char* aTopic,
+                            const char16_t* aData)
+{
+  if (!strcmp(aTopic, "profile-before-change")) {
+    mUserContentSheet = nullptr;
+    mUserChromeSheet  = nullptr;
+  }
+  else if (!strcmp(aTopic, "profile-do-change")) {
+    InitFromProfile();
+  }
+  else if (strcmp(aTopic, "chrome-flush-skin-caches") == 0 ||
+           strcmp(aTopic, "chrome-flush-caches") == 0) {
+    mScrollbarsSheet = nullptr;
+    mFormsSheet = nullptr;
+    mNumberControlSheet = nullptr;
+  }
+  else {
+    NS_NOTREACHED("Unexpected observer topic.");
+  }
+  return NS_OK;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::ScrollbarsSheet()
+{
+  if (!mScrollbarsSheet) {
+    // Scrollbars don't need access to unsafe rules
+    LoadSheetURL("chrome://global/skin/scrollbars.css",
+                 &mScrollbarsSheet, eAuthorSheetFeatures, eCrash);
+  }
+
+  return mScrollbarsSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::FormsSheet()
+{
+  if (!mFormsSheet) {
+    // forms.css needs access to unsafe rules
+    LoadSheetURL("resource://gre-resources/forms.css",
+                 &mFormsSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mFormsSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::NumberControlSheet()
+{
+  if (!sNumberControlEnabled) {
+    return nullptr;
+  }
+
+  if (!mNumberControlSheet) {
+    LoadSheetURL("resource://gre-resources/number-control.css",
+                 &mNumberControlSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mNumberControlSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::UserContentSheet()
+{
+  return mUserContentSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::UserChromeSheet()
+{
+  return mUserChromeSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::UASheet()
+{
+  if (!mUASheet) {
+    LoadSheetURL("resource://gre-resources/ua.css",
+                 &mUASheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mUASheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::HTMLSheet()
+{
+  if (!mHTMLSheet) {
+    LoadSheetURL("resource://gre-resources/html.css",
+                 &mHTMLSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mHTMLSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::MinimalXULSheet()
+{
+  return mMinimalXULSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::XULSheet()
+{
+  return mXULSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::QuirkSheet()
+{
+  return mQuirkSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::SVGSheet()
+{
+  return mSVGSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::MathMLSheet()
+{
+  if (!mMathMLSheet) {
+    LoadSheetURL("resource://gre-resources/mathml.css",
+                 &mMathMLSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mMathMLSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::CounterStylesSheet()
+{
+  return mCounterStylesSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::NoScriptSheet()
+{
+  if (!mNoScriptSheet) {
+    LoadSheetURL("resource://gre-resources/noscript.css",
+                 &mNoScriptSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mNoScriptSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::NoFramesSheet()
+{
+  if (!mNoFramesSheet) {
+    LoadSheetURL("resource://gre-resources/noframes.css",
+                 &mNoFramesSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mNoFramesSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::ChromePreferenceSheet(nsPresContext* aPresContext)
+{
+  if (!mChromePreferenceSheet) {
+    BuildPreferenceSheet(&mChromePreferenceSheet, aPresContext);
+  }
+
+  return mChromePreferenceSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::ContentPreferenceSheet(nsPresContext* aPresContext)
+{
+  if (!mContentPreferenceSheet) {
+    BuildPreferenceSheet(&mContentPreferenceSheet, aPresContext);
+  }
+
+  return mContentPreferenceSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::ContentEditableSheet()
+{
+  if (!mContentEditableSheet) {
+    LoadSheetURL("resource://gre/res/contenteditable.css",
+                 &mContentEditableSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mContentEditableSheet;
+}
+
+StyleSheet*
+nsLayoutStylesheetCache::DesignModeSheet()
+{
+  if (!mDesignModeSheet) {
+    LoadSheetURL("resource://gre/res/designmode.css",
+                 &mDesignModeSheet, eAgentSheetFeatures, eCrash);
+  }
+
+  return mDesignModeSheet;
+}
+
+void
+nsLayoutStylesheetCache::Shutdown()
+{
+  gCSSLoader_Gecko = nullptr;
+  gCSSLoader_Servo = nullptr;
+  gStyleCache_Gecko = nullptr;
+  gStyleCache_Servo = nullptr;
+  MOZ_ASSERT(!gUserContentSheetURL, "Got the URL but never used?");
+}
+
+void
+nsLayoutStylesheetCache::SetUserContentCSSURL(nsIURI* aURI)
+{
+  MOZ_ASSERT(XRE_IsContentProcess(), "Only used in content processes.");
+  gUserContentSheetURL = aURI;
+}
+
+MOZ_DEFINE_MALLOC_SIZE_OF(LayoutStylesheetCacheMallocSizeOf)
+
+NS_IMETHODIMP
+nsLayoutStylesheetCache::CollectReports(nsIHandleReportCallback* aHandleReport,
+                                        nsISupports* aData, bool aAnonymize)
+{
+  MOZ_COLLECT_REPORT(
+    "explicit/layout/style-sheet-cache", KIND_HEAP, UNITS_BYTES,
+    SizeOfIncludingThis(LayoutStylesheetCacheMallocSizeOf),
+    "Memory used for some built-in style sheets.");
+
+  return NS_OK;
+}
+
+
+size_t
+nsLayoutStylesheetCache::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+{
+  size_t n = aMallocSizeOf(this);
+
+  #define MEASURE(s) n += s ? s->SizeOfIncludingThis(aMallocSizeOf) : 0;
+
+  MEASURE(mChromePreferenceSheet);
+  MEASURE(mContentEditableSheet);
+  MEASURE(mContentPreferenceSheet);
+  MEASURE(mCounterStylesSheet);
+  MEASURE(mDesignModeSheet);
+  MEASURE(mFormsSheet);
+  MEASURE(mHTMLSheet);
+  MEASURE(mMathMLSheet);
+  MEASURE(mMinimalXULSheet);
+  MEASURE(mNoFramesSheet);
+  MEASURE(mNoScriptSheet);
+  MEASURE(mNumberControlSheet);
+  MEASURE(mQuirkSheet);
+  MEASURE(mSVGSheet);
+  MEASURE(mScrollbarsSheet);
+  MEASURE(mUASheet);
+  MEASURE(mUserChromeSheet);
+  MEASURE(mUserContentSheet);
+  MEASURE(mXULSheet);
+
+  // Measurement of the following members may be added later if DMD finds it is
+  // worthwhile:
+  // - gCSSLoader_Gecko
+  // - gCSSLoader_Servo
+
+  return n;
+}
+
+nsLayoutStylesheetCache::nsLayoutStylesheetCache(StyleBackendType aType)
+  : mBackendType(aType)
+{
+  nsCOMPtr<nsIObserverService> obsSvc =
+    mozilla::services::GetObserverService();
+  NS_ASSERTION(obsSvc, "No global observer service?");
+
+  if (obsSvc) {
+    obsSvc->AddObserver(this, "profile-before-change", false);
+    obsSvc->AddObserver(this, "profile-do-change", false);
+    obsSvc->AddObserver(this, "chrome-flush-skin-caches", false);
+    obsSvc->AddObserver(this, "chrome-flush-caches", false);
+  }
+
+  InitFromProfile();
+
+  // And make sure that we load our UA sheets.  No need to do this
+  // per-profile, since they're profile-invariant.
+  LoadSheetURL("resource://gre-resources/counterstyles.css",
+               &mCounterStylesSheet, eAgentSheetFeatures, eCrash);
+  LoadSheetURL("chrome://global/content/minimal-xul.css",
+               &mMinimalXULSheet, eAgentSheetFeatures, eCrash);
+  LoadSheetURL("resource://gre-resources/quirk.css",
+               &mQuirkSheet, eAgentSheetFeatures, eCrash);
+  LoadSheetURL("resource://gre/res/svg.css",
+               &mSVGSheet, eAgentSheetFeatures, eCrash);
+  LoadSheetURL("chrome://global/content/xul.css",
+               &mXULSheet, eAgentSheetFeatures, eCrash);
+
+  if (gUserContentSheetURL) {
+    MOZ_ASSERT(XRE_IsContentProcess(), "Only used in content processes.");
+    LoadSheet(gUserContentSheetURL, &mUserContentSheet, eUserSheetFeatures, eLogToConsole);
+    gUserContentSheetURL = nullptr;
+  }
+
+  // The remaining sheets are created on-demand do to their use being rarer
+  // (which helps save memory for Firefox OS apps) or because they need to
+  // be re-loadable in DependentPrefChanged.
+}
+
+nsLayoutStylesheetCache::~nsLayoutStylesheetCache()
+{
+  mozilla::UnregisterWeakMemoryReporter(this);
+}
+
+void
+nsLayoutStylesheetCache::InitMemoryReporter()
+{
+  mozilla::RegisterWeakMemoryReporter(this);
+}
+
+/* static */ nsLayoutStylesheetCache*
+nsLayoutStylesheetCache::For(StyleBackendType aType)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  bool mustInit = !gStyleCache_Gecko && !gStyleCache_Servo;
+  auto& cache = aType == StyleBackendType::Gecko ? gStyleCache_Gecko :
+                                                   gStyleCache_Servo;
+
+  if (!cache) {
+    cache = new nsLayoutStylesheetCache(aType);
+    cache->InitMemoryReporter();
+  }
+
+  if (mustInit) {
+    // Initialization that only needs to be done once for both
+    // nsLayoutStylesheetCaches.
+
+    Preferences::AddBoolVarCache(&sNumberControlEnabled, NUMBER_CONTROL_PREF,
+                                 true);
+
+    // For each pref that controls a CSS feature that a UA style sheet depends
+    // on (such as a pref that enables a property that a UA style sheet uses),
+    // register DependentPrefChanged as a callback to ensure that the relevant
+    // style sheets will be re-parsed.
+    // Preferences::RegisterCallback(&DependentPrefChanged,
+    //                               "layout.css.example-pref.enabled");
+    Preferences::RegisterCallback(&DependentPrefChanged,
+                                  "layout.css.grid.enabled");
+    Preferences::RegisterCallback(&DependentPrefChanged,
+                                  "dom.details_element.enabled");
+  }
+
+  return cache;
+}
+
+void
+nsLayoutStylesheetCache::InitFromProfile()
+{
+  nsCOMPtr<nsIXULRuntime> appInfo = do_GetService("@mozilla.org/xre/app-info;1");
+  if (appInfo) {
+    bool inSafeMode = false;
+    appInfo->GetInSafeMode(&inSafeMode);
+    if (inSafeMode)
+      return;
+  }
+  nsCOMPtr<nsIFile> contentFile;
+  nsCOMPtr<nsIFile> chromeFile;
+
+  NS_GetSpecialDirectory(NS_APP_USER_CHROME_DIR,
+                         getter_AddRefs(contentFile));
+  if (!contentFile) {
+    // if we don't have a profile yet, that's OK!
+    return;
+  }
+
+  contentFile->Clone(getter_AddRefs(chromeFile));
+  if (!chromeFile) return;
+
+  contentFile->Append(NS_LITERAL_STRING("userContent.css"));
+  chromeFile->Append(NS_LITERAL_STRING("userChrome.css"));
+
+  LoadSheetFile(contentFile, &mUserContentSheet, eUserSheetFeatures, eLogToConsole);
+  LoadSheetFile(chromeFile, &mUserChromeSheet, eUserSheetFeatures, eLogToConsole);
+}
+
+void
+nsLayoutStylesheetCache::LoadSheetURL(const char* aURL,
+                                      RefPtr<StyleSheet>* aSheet,
+                                      SheetParsingMode aParsingMode,
+                                      FailureAction aFailureAction)
+{
+  nsCOMPtr<nsIURI> uri;
+  NS_NewURI(getter_AddRefs(uri), aURL);
+  LoadSheet(uri, aSheet, aParsingMode, aFailureAction);
+  if (!aSheet) {
+    NS_ERROR(nsPrintfCString("Could not load %s", aURL).get());
+  }
+}
+
+void
+nsLayoutStylesheetCache::LoadSheetFile(nsIFile* aFile,
+                                       RefPtr<StyleSheet>* aSheet,
+                                       SheetParsingMode aParsingMode,
+                                       FailureAction aFailureAction)
+{
+  bool exists = false;
+  aFile->Exists(&exists);
+
+  if (!exists) return;
+
+  nsCOMPtr<nsIURI> uri;
+  NS_NewFileURI(getter_AddRefs(uri), aFile);
+
+  LoadSheet(uri, aSheet, aParsingMode, aFailureAction);
+}
+
+#ifdef MOZ_CRASHREPORTER
+static inline nsresult
+ComputeCRC32(nsIFile* aFile, uint32_t* aResult)
+{
+  PRFileDesc* fd;
+  nsresult rv = aFile->OpenNSPRFileDesc(PR_RDONLY, 0, &fd);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t crc = crc32(0, nullptr, 0);
+
+  unsigned char buf[512];
+  int32_t n;
+  while ((n = PR_Read(fd, buf, sizeof(buf))) > 0) {
+    crc = crc32(crc, buf, n);
+  }
+  PR_Close(fd);
+
+  if (n < 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *aResult = crc;
+  return NS_OK;
+}
+
+static void
+ListInterestingFiles(nsString& aAnnotation, nsIFile* aFile,
+                     const nsTArray<nsString>& aInterestingFilenames)
+{
+  nsString filename;
+  aFile->GetLeafName(filename);
+  for (const nsString& interestingFilename : aInterestingFilenames) {
+    if (interestingFilename == filename) {
+      nsString path;
+      aFile->GetPath(path);
+      aAnnotation.AppendLiteral("  ");
+      aAnnotation.Append(path);
+      aAnnotation.AppendLiteral(" (");
+      int64_t size;
+      if (NS_SUCCEEDED(aFile->GetFileSize(&size))) {
+        aAnnotation.AppendPrintf("%ld", size);
+      } else {
+        aAnnotation.AppendLiteral("???");
+      }
+      aAnnotation.AppendLiteral(" bytes, crc32 = ");
+      uint32_t crc;
+      nsresult rv = ComputeCRC32(aFile, &crc);
+      if (NS_SUCCEEDED(rv)) {
+        aAnnotation.AppendPrintf("0x%08x)\n", crc);
+      } else {
+        aAnnotation.AppendPrintf("error 0x%08x)\n", uint32_t(rv));
+      }
+      return;
+    }
+  }
+
+  bool isDir = false;
+  aFile->IsDirectory(&isDir);
+
+  if (!isDir) {
+    return;
+  }
+
+  nsCOMPtr<nsISimpleEnumerator> entries;
+  if (NS_FAILED(aFile->GetDirectoryEntries(getter_AddRefs(entries)))) {
+    aAnnotation.AppendLiteral("  (failed to enumerated directory)\n");
+    return;
+  }
+
+  for (;;) {
+    bool hasMore = false;
+    if (NS_FAILED(entries->HasMoreElements(&hasMore))) {
+      aAnnotation.AppendLiteral("  (failed during directory enumeration)\n");
+      return;
+    }
+    if (!hasMore) {
+      break;
+    }
+
+    nsCOMPtr<nsISupports> entry;
+    if (NS_FAILED(entries->GetNext(getter_AddRefs(entry)))) {
+      aAnnotation.AppendLiteral("  (failed during directory enumeration)\n");
+      return;
+    }
+
+    nsCOMPtr<nsIFile> file = do_QueryInterface(entry);
+    if (file) {
+      ListInterestingFiles(aAnnotation, file, aInterestingFilenames);
+    }
+  }
+}
+
+// Generate a crash report annotation to help debug issues with style
+// sheets failing to load (bug 1194856).
+static void
+AnnotateCrashReport(nsIURI* aURI)
+{
+  nsAutoCString spec;
+  nsAutoCString scheme;
+  nsDependentCSubstring filename;
+  if (aURI) {
+    spec = aURI->GetSpecOrDefault();
+    aURI->GetScheme(scheme);
+    int32_t i = spec.RFindChar('/');
+    if (i != -1) {
+      filename.Rebind(spec, i + 1);
+    }
+  }
+
+  nsString annotation;
+
+  // The URL of the sheet that failed to load.
+  annotation.AppendLiteral("Error loading sheet: ");
+  annotation.Append(NS_ConvertUTF8toUTF16(spec).get());
+  annotation.Append('\n');
+
+  annotation.AppendLiteral("NS_ERROR_FILE_CORRUPTION reason: ");
+  if (nsZipArchive::sFileCorruptedReason) {
+    annotation.Append(NS_ConvertUTF8toUTF16(nsZipArchive::sFileCorruptedReason).get());
+    annotation.Append('\n');
+  } else {
+    annotation.AppendLiteral("(none)\n");
+  }
+
+  // The jar: or file: URL that the sheet's resource: or chrome: URL
+  // resolves to.
+  if (scheme.EqualsLiteral("resource")) {
+    annotation.AppendLiteral("Real location: ");
+    nsCOMPtr<nsISubstitutingProtocolHandler> handler;
+    nsCOMPtr<nsIIOService> io(do_GetIOService());
+    if (io) {
+      nsCOMPtr<nsIProtocolHandler> ph;
+      io->GetProtocolHandler(scheme.get(), getter_AddRefs(ph));
+      if (ph) {
+        handler = do_QueryInterface(ph);
+      }
+    }
+    if (!handler) {
+      annotation.AppendLiteral("(ResolveURI failed)\n");
+    } else {
+      nsAutoCString resolvedSpec;
+      handler->ResolveURI(aURI, resolvedSpec);
+      annotation.Append(NS_ConvertUTF8toUTF16(resolvedSpec));
+      annotation.Append('\n');
+    }
+  } else if (scheme.EqualsLiteral("chrome")) {
+    annotation.AppendLiteral("Real location: ");
+    nsCOMPtr<nsIChromeRegistry> reg =
+      mozilla::services::GetChromeRegistryService();
+    if (!reg) {
+      annotation.AppendLiteral("(no chrome registry)\n");
+    } else {
+      nsCOMPtr<nsIURI> resolvedURI;
+      reg->ConvertChromeURL(aURI, getter_AddRefs(resolvedURI));
+      if (!resolvedURI) {
+        annotation.AppendLiteral("(ConvertChromeURL failed)\n");
+      } else {
+        annotation.Append(
+          NS_ConvertUTF8toUTF16(resolvedURI->GetSpecOrDefault()));
+        annotation.Append('\n');
+      }
+    }
+  }
+
+  nsTArray<nsString> interestingFiles;
+  interestingFiles.AppendElement(NS_LITERAL_STRING("chrome.manifest"));
+  interestingFiles.AppendElement(NS_LITERAL_STRING("omni.ja"));
+  interestingFiles.AppendElement(NS_ConvertUTF8toUTF16(filename));
+
+  annotation.AppendLiteral("GRE directory: ");
+  nsCOMPtr<nsIFile> file;
+  nsDirectoryService::gService->Get(NS_GRE_DIR, NS_GET_IID(nsIFile),
+                                    getter_AddRefs(file));
+  if (file) {
+    // The Firefox installation directory.
+    nsString path;
+    file->GetPath(path);
+    annotation.Append(path);
+    annotation.Append('\n');
+
+    // List interesting files -- any chrome.manifest or omni.ja file or any file
+    // whose name is the sheet's filename -- under the Firefox installation
+    // directory.
+    annotation.AppendLiteral("Interesting files in the GRE directory:\n");
+    ListInterestingFiles(annotation, file, interestingFiles);
+
+    // If the Firefox installation directory has a chrome.manifest file, let's
+    // see what's in it.
+    file->Append(NS_LITERAL_STRING("chrome.manifest"));
+    bool exists = false;
+    file->Exists(&exists);
+    if (exists) {
+      annotation.AppendLiteral("Contents of chrome.manifest:\n[[[\n");
+      PRFileDesc* fd;
+      if (NS_SUCCEEDED(file->OpenNSPRFileDesc(PR_RDONLY, 0, &fd))) {
+        nsCString contents;
+        char buf[512];
+        int32_t n;
+        while ((n = PR_Read(fd, buf, sizeof(buf))) > 0) {
+          contents.Append(buf, n);
+        }
+        if (n < 0) {
+          annotation.AppendLiteral("  (error while reading)\n");
+        } else {
+          annotation.Append(NS_ConvertUTF8toUTF16(contents));
+        }
+        PR_Close(fd);
+      }
+      annotation.AppendLiteral("]]]\n");
+    }
+  } else {
+    annotation.AppendLiteral("(none)\n");
+  }
+
+  // The jar: or file: URL prefix that chrome: and resource: URLs get translated
+  // to.
+  annotation.AppendLiteral("GRE omnijar URI string: ");
+  nsCString uri;
+  nsresult rv = Omnijar::GetURIString(Omnijar::GRE, uri);
+  if (NS_FAILED(rv)) {
+    annotation.AppendLiteral("(failed)\n");
+  } else {
+    annotation.Append(NS_ConvertUTF8toUTF16(uri));
+    annotation.Append('\n');
+  }
+
+  RefPtr<nsZipArchive> zip = Omnijar::GetReader(Omnijar::GRE);
+  if (zip) {
+    // List interesting files in the GRE omnijar.
+    annotation.AppendLiteral("Interesting files in the GRE omnijar:\n");
+    nsZipFind* find;
+    rv = zip->FindInit(nullptr, &find);
+    if (NS_FAILED(rv)) {
+      annotation.AppendPrintf("  (FindInit failed with 0x%08x)\n", rv);
+    } else if (!find) {
+      annotation.AppendLiteral("  (FindInit returned null)\n");
+    } else {
+      const char* result;
+      uint16_t len;
+      while (NS_SUCCEEDED(find->FindNext(&result, &len))) {
+        nsCString itemPathname;
+        nsString itemFilename;
+        itemPathname.Append(result, len);
+        int32_t i = itemPathname.RFindChar('/');
+        if (i != -1) {
+          itemFilename = NS_ConvertUTF8toUTF16(Substring(itemPathname, i + 1));
+        }
+        for (const nsString& interestingFile : interestingFiles) {
+          if (interestingFile == itemFilename) {
+            annotation.AppendLiteral("  ");
+            annotation.Append(NS_ConvertUTF8toUTF16(itemPathname));
+            nsZipItem* item = zip->GetItem(itemPathname.get());
+            if (!item) {
+              annotation.AppendLiteral(" (GetItem failed)\n");
+            } else {
+              annotation.AppendPrintf(" (%d bytes, crc32 = 0x%08x)\n",
+                                      item->RealSize(),
+                                      item->CRC32());
+            }
+            break;
+          }
+        }
+      }
+      delete find;
+    }
+  } else {
+    annotation.AppendLiteral("No GRE omnijar\n");
+  }
+
+  CrashReporter::AnnotateCrashReport(NS_LITERAL_CSTRING("SheetLoadFailure"),
+                                     NS_ConvertUTF16toUTF8(annotation));
+}
+#endif
+
+static void
+ErrorLoadingSheet(nsIURI* aURI, const char* aMsg, FailureAction aFailureAction)
+{
+  nsPrintfCString errorMessage("%s loading built-in stylesheet '%s'",
+                               aMsg,
+                               aURI ? aURI->GetSpecOrDefault().get() : "");
+  if (aFailureAction == eLogToConsole) {
+    nsCOMPtr<nsIConsoleService> cs = do_GetService(NS_CONSOLESERVICE_CONTRACTID);
+    if (cs) {
+      cs->LogStringMessage(NS_ConvertUTF8toUTF16(errorMessage).get());
+      return;
+    }
+  }
+
+#ifdef MOZ_CRASHREPORTER
+  AnnotateCrashReport(aURI);
+#endif
+  NS_RUNTIMEABORT(errorMessage.get());
+}
+
+void
+nsLayoutStylesheetCache::LoadSheet(nsIURI* aURI,
+                                   RefPtr<StyleSheet>* aSheet,
+                                   SheetParsingMode aParsingMode,
+                                   FailureAction aFailureAction)
+{
+  if (!aURI) {
+    ErrorLoadingSheet(aURI, "null URI", eCrash);
+    return;
+  }
+
+  auto& loader = mBackendType == StyleBackendType::Gecko ?
+    gCSSLoader_Gecko :
+    gCSSLoader_Servo;
+
+  if (!loader) {
+    loader = new mozilla::css::Loader(mBackendType);
+    if (!loader) {
+      ErrorLoadingSheet(aURI, "no Loader", eCrash);
+      return;
+    }
+  }
+
+#ifdef MOZ_CRASHREPORTER
+  nsZipArchive::sFileCorruptedReason = nullptr;
+#endif
+  nsresult rv = loader->LoadSheetSync(aURI, aParsingMode, true, aSheet);
+  if (NS_FAILED(rv)) {
+    ErrorLoadingSheet(aURI,
+      nsPrintfCString("LoadSheetSync failed with error %x", rv).get(),
+      aFailureAction);
+  }
+}
+
+/* static */ void
+nsLayoutStylesheetCache::InvalidateSheet(RefPtr<StyleSheet>* aGeckoSheet,
+                                         RefPtr<StyleSheet>* aServoSheet)
+{
+  MOZ_ASSERT(gCSSLoader_Gecko || gCSSLoader_Servo,
+             "pref changed before we loaded a sheet?");
+
+  const bool gotGeckoSheet = aGeckoSheet && *aGeckoSheet;
+  const bool gotServoSheet = aServoSheet && *aServoSheet;
+
+  // Make sure sheets have the expected types
+  MOZ_ASSERT(!gotGeckoSheet || (*aGeckoSheet)->IsGecko());
+  MOZ_ASSERT(!gotServoSheet || (*aServoSheet)->IsServo());
+  // Make sure the URIs match
+  MOZ_ASSERT(!gotServoSheet || !gotGeckoSheet ||
+             (*aGeckoSheet)->GetSheetURI() == (*aServoSheet)->GetSheetURI(),
+             "Sheets passed should have the same URI");
+
+  nsIURI* uri;
+  if (gotGeckoSheet) {
+    uri = (*aGeckoSheet)->GetSheetURI();
+  } else if (gotServoSheet) {
+    uri = (*aServoSheet)->GetSheetURI();
+  } else {
+    return;
+  }
+
+  if (gCSSLoader_Gecko) {
+    gCSSLoader_Gecko->ObsoleteSheet(uri);
+  }
+  if (gCSSLoader_Servo) {
+    gCSSLoader_Servo->ObsoleteSheet(uri);
+  }
+  if (gotGeckoSheet) {
+    *aGeckoSheet = nullptr;
+  }
+  if (gotServoSheet) {
+    *aServoSheet = nullptr;
+  }
+}
+
+/* static */ void
+nsLayoutStylesheetCache::DependentPrefChanged(const char* aPref, void* aData)
+{
+  MOZ_ASSERT(gStyleCache_Gecko || gStyleCache_Servo,
+             "pref changed after shutdown?");
+
+  // Cause any UA style sheets whose parsing depends on the value of prefs
+  // to be re-parsed by dropping the sheet from gCSSLoader_{Gecko,Servo}'s cache
+  // then setting our cached sheet pointer to null.  This will only work for
+  // sheets that are loaded lazily.
+
+#define INVALIDATE(sheet_) \
+  InvalidateSheet(gStyleCache_Gecko ? &gStyleCache_Gecko->sheet_ : nullptr, \
+                  gStyleCache_Servo ? &gStyleCache_Servo->sheet_ : nullptr);
+
+  INVALIDATE(mUASheet);  // for layout.css.grid.enabled
+  INVALIDATE(mHTMLSheet); // for dom.details_element.enabled
+
+#undef INVALIDATE
+}
+
+/* static */ void
+nsLayoutStylesheetCache::InvalidatePreferenceSheets()
+{
+  if (gStyleCache_Gecko) {
+    gStyleCache_Gecko->mContentPreferenceSheet = nullptr;
+    gStyleCache_Gecko->mChromePreferenceSheet = nullptr;
+  }
+  if (gStyleCache_Servo) {
+    gStyleCache_Servo->mContentPreferenceSheet = nullptr;
+    gStyleCache_Servo->mChromePreferenceSheet = nullptr;
+  }
+}
+
+void
+nsLayoutStylesheetCache::BuildPreferenceSheet(RefPtr<StyleSheet>* aSheet,
+                                              nsPresContext* aPresContext)
+{
+  if (mBackendType == StyleBackendType::Gecko) {
+    *aSheet = new CSSStyleSheet(eAgentSheetFeatures, CORS_NONE,
+                                mozilla::net::RP_Default);
+  } else {
+    *aSheet = new ServoStyleSheet(eAgentSheetFeatures, CORS_NONE,
+                                  mozilla::net::RP_Default, dom::SRIMetadata());
+  }
+
+  StyleSheet* sheet = *aSheet;
+
+  nsCOMPtr<nsIURI> uri;
+  NS_NewURI(getter_AddRefs(uri), "about:PreferenceStyleSheet", nullptr);
+  MOZ_ASSERT(uri, "URI creation shouldn't fail");
+
+  sheet->SetURIs(uri, uri, uri);
+  sheet->SetComplete();
+
+  static const uint32_t kPreallocSize = 1024;
+
+  nsString sheetText;
+  sheetText.SetCapacity(kPreallocSize);
+
+#define NS_GET_R_G_B(color_) \
+  NS_GET_R(color_), NS_GET_G(color_), NS_GET_B(color_)
+
+  sheetText.AppendLiteral(
+      "@namespace url(http://www.w3.org/1999/xhtml);\n"
+      "@namespace svg url(http://www.w3.org/2000/svg);\n");
+
+  // Rules for link styling.
+  nscolor linkColor = aPresContext->DefaultLinkColor();
+  nscolor activeColor = aPresContext->DefaultActiveLinkColor();
+  nscolor visitedColor = aPresContext->DefaultVisitedLinkColor();
+
+  sheetText.AppendPrintf(
+      "*|*:link { color: #%02x%02x%02x; }\n"
+      "*|*:any-link:active { color: #%02x%02x%02x; }\n"
+      "*|*:visited { color: #%02x%02x%02x; }\n",
+      NS_GET_R_G_B(linkColor),
+      NS_GET_R_G_B(activeColor),
+      NS_GET_R_G_B(visitedColor));
+
+  bool underlineLinks =
+    aPresContext->GetCachedBoolPref(kPresContext_UnderlineLinks);
+  sheetText.AppendPrintf(
+      "*|*:any-link%s { text-decoration: %s; }\n",
+      underlineLinks ? ":not(svg|a)" : "",
+      underlineLinks ? "underline" : "none");
+
+  // Rules for focus styling.
+
+  bool focusRingOnAnything = aPresContext->GetFocusRingOnAnything();
+  uint8_t focusRingWidth = aPresContext->FocusRingWidth();
+  uint8_t focusRingStyle = aPresContext->GetFocusRingStyle();
+
+  if ((focusRingWidth != 1 && focusRingWidth <= 4) || focusRingOnAnything) {
+    if (focusRingWidth != 1) {
+      // If the focus ring width is different from the default, fix buttons
+      // with rings.
+      sheetText.AppendPrintf(
+          "button::-moz-focus-inner, input[type=\"reset\"]::-moz-focus-inner, "
+          "input[type=\"button\"]::-moz-focus-inner, "
+          "input[type=\"submit\"]::-moz-focus-inner { "
+          "padding: 1px 2px 1px 2px; "
+          "border: %dpx %s transparent !important; }\n",
+          focusRingWidth,
+          focusRingStyle == 0 ? "solid" : "dotted");
+
+      sheetText.AppendLiteral(
+          "button:focus::-moz-focus-inner, "
+          "input[type=\"reset\"]:focus::-moz-focus-inner, "
+          "input[type=\"button\"]:focus::-moz-focus-inner, "
+          "input[type=\"submit\"]:focus::-moz-focus-inner { "
+          "border-color: ButtonText !important; }\n");
+    }
+
+    sheetText.AppendPrintf(
+        "%s { outline: %dpx %s !important; %s}\n",
+        focusRingOnAnything ?
+          ":focus" :
+          "*|*:link:focus, *|*:visited:focus",
+        focusRingWidth,
+        focusRingStyle == 0 ? // solid
+          "solid -moz-mac-focusring" : "dotted WindowText",
+        focusRingStyle == 0 ? // solid
+          "-moz-outline-radius: 3px; outline-offset: 1px; " : "");
+  }
+
+  if (aPresContext->GetUseFocusColors()) {
+    nscolor focusText = aPresContext->FocusTextColor();
+    nscolor focusBG = aPresContext->FocusBackgroundColor();
+    sheetText.AppendPrintf(
+        "*:focus, *:focus > font { color: #%02x%02x%02x !important; "
+        "background-color: #%02x%02x%02x !important; }\n",
+        NS_GET_R_G_B(focusText),
+        NS_GET_R_G_B(focusBG));
+  }
+
+  NS_ASSERTION(sheetText.Length() <= kPreallocSize,
+               "kPreallocSize should be big enough to build preference style "
+               "sheet without reallocation");
+
+  if (sheet->IsGecko()) {
+    sheet->AsGecko()->ReparseSheet(sheetText);
+  } else {
+    nsresult rv = sheet->AsServo()->ParseSheet(sheetText, uri, uri, nullptr, 0);
+    // Parsing the about:PreferenceStyleSheet URI can only fail on OOM. If we
+    // are OOM before we parsed any documents we might as well abort.
+    MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+  }
+
+#undef NS_GET_R_G_B
+}
+
+mozilla::StaticRefPtr<nsLayoutStylesheetCache>
+nsLayoutStylesheetCache::gStyleCache_Gecko;
+
+mozilla::StaticRefPtr<nsLayoutStylesheetCache>
+nsLayoutStylesheetCache::gStyleCache_Servo;
+
+mozilla::StaticRefPtr<mozilla::css::Loader>
+nsLayoutStylesheetCache::gCSSLoader_Gecko;
+
+mozilla::StaticRefPtr<mozilla::css::Loader>
+nsLayoutStylesheetCache::gCSSLoader_Servo;
+
+mozilla::StaticRefPtr<nsIURI>
+nsLayoutStylesheetCache::gUserContentSheetURL;