Issue #1263 - Part 1: Remove DiskSpaceWatcher

20 files changed, 3 insertions, 537 deletions

diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index cd998c31c..74afef452 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -4427,18 +4427,6 @@ CreateStorageConnection(nsIFile* aDBFile,
   nsresult rv;
   bool exists;
 
-  if (IndexedDatabaseManager::InLowDiskSpaceMode()) {
-    rv = aDBFile->Exists(&exists);
-    if (NS_WARN_IF(NS_FAILED(rv))) {
-      return rv;
-    }
-
-    if (!exists) {
-      NS_WARNING("Refusing to create database because disk space is low!");
-      return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-    }
-  }
-
   nsCOMPtr<nsIFileURL> dbFileUrl;
   rv = GetDatabaseFileURL(aDBFile,
                           aPersistenceType,
@@ -19103,23 +19091,6 @@ DatabaseMaintenance::DetermineMaintenanceAction(
     return NS_OK;
   }
 
-  bool lowDiskSpace = IndexedDatabaseManager::InLowDiskSpaceMode();
-
-  if (QuotaManager::IsRunningXPCShellTests()) {
-    // If we're running XPCShell then we want to test both the low disk space
-    // and normal disk space code paths so pick semi-randomly based on the
-    // current time.
-    lowDiskSpace = ((PR_Now() / PR_USEC_PER_MSEC) % 2) == 0;
-  }
-
-  // If we're low on disk space then the best we can hope for is that an
-  // incremental vacuum might free some space. That is a journaled operation so
-  // it may not be possible even then.
-  if (lowDiskSpace) {
-    *aMaintenanceAction = MaintenanceAction::IncrementalVacuum;
-    return NS_OK;
-  }
-
   // This method shouldn't make any permanent changes to the database, so make
   // sure everything gets rolled back when we leave.
   mozStorageTransaction transaction(aConnection,
@@ -24233,11 +24204,6 @@ CreateFileOp::DoDatabaseWork()
                  "CreateFileOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    NS_WARNING("Refusing to create file because disk space is low!");
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
   if (NS_WARN_IF(QuotaManager::IsShuttingDown()) || !OperationMayProceed()) {
     IDB_REPORT_INTERNAL_ERR();
     return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
@@ -24378,10 +24344,6 @@ CreateObjectStoreOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "CreateObjectStoreOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not creating an object store with the same name as
@@ -24705,10 +24667,6 @@ RenameObjectStoreOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "RenameObjectStoreOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not renaming an object store with the same name as
@@ -24798,7 +24756,6 @@ CreateIndexOp::InsertDataFromObjectStore(DatabaseConnection* aConnection)
 {
   MOZ_ASSERT(aConnection);
   aConnection->AssertIsOnConnectionThread();
-  MOZ_ASSERT(!IndexedDatabaseManager::InLowDiskSpaceMode());
   MOZ_ASSERT(mMaybeUniqueIndexTable);
 
   PROFILER_LABEL("IndexedDB",
@@ -24849,7 +24806,6 @@ CreateIndexOp::InsertDataFromObjectStoreInternal(
 {
   MOZ_ASSERT(aConnection);
   aConnection->AssertIsOnConnectionThread();
-  MOZ_ASSERT(!IndexedDatabaseManager::InLowDiskSpaceMode());
   MOZ_ASSERT(mMaybeUniqueIndexTable);
 
   DebugOnly<void*> storageConnection = aConnection->GetStorageConnection();
@@ -24926,10 +24882,6 @@ CreateIndexOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "CreateIndexOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not creating an index with the same name and object
@@ -25806,10 +25758,6 @@ RenameIndexOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "RenameIndexOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
 #ifdef DEBUG
   {
     // Make sure that we're not renaming an index with the same name as another
@@ -26294,10 +26242,6 @@ ObjectStoreAddOrPutRequestOp::DoDatabaseWork(DatabaseConnection* aConnection)
                  "ObjectStoreAddOrPutRequestOp::DoDatabaseWork",
                  js::ProfileEntry::Category::STORAGE);
 
-  if (NS_WARN_IF(IndexedDatabaseManager::InLowDiskSpaceMode())) {
-    return NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR;
-  }
-
   DatabaseConnection::AutoSavepoint autoSave;
   nsresult rv = autoSave.Start(Transaction());
   if (NS_WARN_IF(NS_FAILED(rv))) {
diff --git a/dom/indexedDB/IndexedDatabaseManager.cpp b/dom/indexedDB/IndexedDatabaseManager.cpp
index 62ba51c08..213de5cc9 100644
--- a/dom/indexedDB/IndexedDatabaseManager.cpp
+++ b/dom/indexedDB/IndexedDatabaseManager.cpp
@@ -8,11 +8,9 @@
 
 #include "chrome/common/ipc_channel.h" // for IPC::Channel::kMaximumMessageSize
 #include "nsIConsoleService.h"
-#include "nsIDiskSpaceWatcher.h"
 #include "nsIDOMWindow.h"
 #include "nsIEventTarget.h"
 #include "nsIFile.h"
-#include "nsIObserverService.h"
 #include "nsIScriptError.h"
 #include "nsIScriptGlobalObject.h"
 
@@ -64,11 +62,6 @@
 
 #define IDB_STR "indexedDB"
 
-// The two possible values for the data argument when receiving the disk space
-// observer notification.
-#define LOW_DISK_SPACE_DATA_FULL "full"
-#define LOW_DISK_SPACE_DATA_FREE "free"
-
 namespace mozilla {
 namespace dom {
 namespace indexedDB {
@@ -313,8 +306,6 @@ Atomic<IndexedDatabaseManager::LoggingMode>
   IndexedDatabaseManager::sLoggingMode(
     IndexedDatabaseManager::Logging_Disabled);
 
-mozilla::Atomic<bool> IndexedDatabaseManager::sLowDiskSpaceMode(false);
-
 // static
 IndexedDatabaseManager*
 IndexedDatabaseManager::GetOrCreate()
@@ -329,24 +320,6 @@ IndexedDatabaseManager::GetOrCreate()
   if (!gDBManager) {
     sIsMainProcess = XRE_IsParentProcess();
 
-    if (sIsMainProcess && Preferences::GetBool("disk_space_watcher.enabled", false)) {
-      // See if we're starting up in low disk space conditions.
-      nsCOMPtr<nsIDiskSpaceWatcher> watcher =
-        do_GetService(DISKSPACEWATCHER_CONTRACTID);
-      if (watcher) {
-        bool isDiskFull;
-        if (NS_SUCCEEDED(watcher->GetIsDiskFull(&isDiskFull))) {
-          sLowDiskSpaceMode = isDiskFull;
-        }
-        else {
-          NS_WARNING("GetIsDiskFull failed!");
-        }
-      }
-      else {
-        NS_WARNING("No disk space watcher component available!");
-      }
-    }
-
     RefPtr<IndexedDatabaseManager> instance(new IndexedDatabaseManager());
 
     nsresult rv = instance->Init();
@@ -380,13 +353,6 @@ IndexedDatabaseManager::Init()
   // During Init() we can't yet call IsMainProcess(), just check sIsMainProcess
   // directly.
   if (sIsMainProcess) {
-    nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
-    NS_ENSURE_STATE(obs);
-
-    nsresult rv =
-      obs->AddObserver(this, DISKSPACEWATCHER_OBSERVER_TOPIC, false);
-    NS_ENSURE_SUCCESS(rv, rv);
-
     mDeleteTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
     NS_ENSURE_STATE(mDeleteTimer);
 
@@ -680,16 +646,6 @@ IndexedDatabaseManager::IsMainProcess()
   return sIsMainProcess;
 }
 
-//static
-bool
-IndexedDatabaseManager::InLowDiskSpaceMode()
-{
-  NS_ASSERTION(gDBManager,
-               "InLowDiskSpaceMode() called before indexedDB has been "
-               "initialized!");
-  return sLowDiskSpaceMode;
-}
-
 // static
 IndexedDatabaseManager::LoggingMode
 IndexedDatabaseManager::GetLoggingMode()
@@ -1087,36 +1043,7 @@ IndexedDatabaseManager::GetLocale()
 
 NS_IMPL_ADDREF(IndexedDatabaseManager)
 NS_IMPL_RELEASE_WITH_DESTROY(IndexedDatabaseManager, Destroy())
-NS_IMPL_QUERY_INTERFACE(IndexedDatabaseManager, nsIObserver, nsITimerCallback)
-
-NS_IMETHODIMP
-IndexedDatabaseManager::Observe(nsISupports* aSubject, const char* aTopic,
-                                const char16_t* aData)
-{
-  NS_ASSERTION(IsMainProcess(), "Wrong process!");
-  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
-
-  if (!strcmp(aTopic, DISKSPACEWATCHER_OBSERVER_TOPIC)) {
-    NS_ASSERTION(aData, "No data?!");
-
-    const nsDependentString data(aData);
-
-    if (data.EqualsLiteral(LOW_DISK_SPACE_DATA_FULL)) {
-      sLowDiskSpaceMode = true;
-    }
-    else if (data.EqualsLiteral(LOW_DISK_SPACE_DATA_FREE)) {
-      sLowDiskSpaceMode = false;
-    }
-    else {
-      NS_NOTREACHED("Unknown data value!");
-    }
-
-    return NS_OK;
-  }
-
-   NS_NOTREACHED("Unknown topic!");
-   return NS_ERROR_UNEXPECTED;
-}
+NS_IMPL_QUERY_INTERFACE(IndexedDatabaseManager, nsITimerCallback)
 
 NS_IMETHODIMP
 IndexedDatabaseManager::Notify(nsITimer* aTimer)
diff --git a/dom/indexedDB/IndexedDatabaseManager.h b/dom/indexedDB/IndexedDatabaseManager.h
index d63c548ec..fb4376426 100644
--- a/dom/indexedDB/IndexedDatabaseManager.h
+++ b/dom/indexedDB/IndexedDatabaseManager.h
@@ -7,8 +7,6 @@
 #ifndef mozilla_dom_indexeddatabasemanager_h__
 #define mozilla_dom_indexeddatabasemanager_h__
 
-#include "nsIObserver.h"
-
 #include "js/TypeDecls.h"
 #include "mozilla/Atomics.h"
 #include "mozilla/dom/quota/PersistenceType.h"
@@ -43,8 +41,7 @@ class FileManagerInfo;
 } // namespace indexedDB
 
 class IndexedDatabaseManager final
-  : public nsIObserver
-  , public nsITimerCallback
+  : public nsITimerCallback
 {
   typedef mozilla::dom::quota::PersistenceType PersistenceType;
   typedef mozilla::dom::quota::QuotaManager QuotaManager;
@@ -62,7 +59,6 @@ public:
   };
 
   NS_DECL_ISUPPORTS
-  NS_DECL_NSIOBSERVER
   NS_DECL_NSITIMERCALLBACK
 
   // Returns a non-owning reference.
@@ -87,16 +83,6 @@ public:
 #endif
 
   static bool
-  InLowDiskSpaceMode()
-#ifdef DEBUG
-  ;
-#else
-  {
-    return !!sLowDiskSpaceMode;
-  }
-#endif
-
-  static bool
   InTestingMode();
 
   static bool
@@ -244,7 +230,6 @@ private:
   static bool sFullSynchronousMode;
   static LazyLogModule sLoggingModule;
   static Atomic<LoggingMode> sLoggingMode;
-  static mozilla::Atomic<bool> sLowDiskSpaceMode;
 };
 
 } // namespace dom
diff --git a/dom/storage/DOMStorageCache.cpp b/dom/storage/DOMStorageCache.cpp
index a2b5a6f73..ee9a22e96 100644
--- a/dom/storage/DOMStorageCache.cpp
+++ b/dom/storage/DOMStorageCache.cpp
@@ -205,11 +205,6 @@ DOMStorageCache::ProcessUsageDelta(const DOMStorage* aStorage, int64_t aDelta)
 bool
 DOMStorageCache::ProcessUsageDelta(uint32_t aGetDataSetIndex, const int64_t aDelta)
 {
-  // Check if we are in a low disk space situation
-  if (aDelta > 0 && mManager && mManager->IsLowDiskSpace()) {
-    return false;
-  }
-
   // Check limit per this origin
   Data& data = mData[aGetDataSetIndex];
   uint64_t newOriginUsage = data.mOriginQuotaUsage + aDelta;
diff --git a/dom/storage/DOMStorageIPC.cpp b/dom/storage/DOMStorageIPC.cpp
index a8cd745f1..9d87a5788 100644
--- a/dom/storage/DOMStorageIPC.cpp
+++ b/dom/storage/DOMStorageIPC.cpp
@@ -11,7 +11,6 @@
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/Unused.h"
-#include "nsIDiskSpaceWatcher.h"
 #include "nsThreadUtils.h"
 
 namespace mozilla {
@@ -321,22 +320,6 @@ private:
       mozilla::Unused << mParent->SendOriginsHavingData(scopes);
     }
 
-    // We need to check if the device is in a low disk space situation, so
-    // we can forbid in that case any write in localStorage.
-    nsCOMPtr<nsIDiskSpaceWatcher> diskSpaceWatcher =
-      do_GetService("@mozilla.org/toolkit/disk-space-watcher;1");
-    if (!diskSpaceWatcher) {
-      return NS_OK;
-    }
-
-    bool lowDiskSpace = false;
-    diskSpaceWatcher->GetIsDiskFull(&lowDiskSpace);
-
-    if (lowDiskSpace) {
-      mozilla::Unused << mParent->SendObserve(
-        nsDependentCString("low-disk-space"), EmptyString(), EmptyCString());
-    }
-
     return NS_OK;
   }
 
diff --git a/dom/storage/DOMStorageManager.cpp b/dom/storage/DOMStorageManager.cpp
index 156e846ba..8f50fcfb4 100644
--- a/dom/storage/DOMStorageManager.cpp
+++ b/dom/storage/DOMStorageManager.cpp
@@ -103,7 +103,6 @@ NS_IMPL_ISUPPORTS(DOMStorageManager,
 DOMStorageManager::DOMStorageManager(DOMStorage::StorageType aType)
   : mCaches(8)
   , mType(aType)
-  , mLowDiskSpace(false)
 {
   DOMStorageObserver* observer = DOMStorageObserver::Self();
   NS_ASSERTION(observer, "No DOMStorageObserver, cannot observe private data delete notifications!");
@@ -566,22 +565,6 @@ DOMStorageManager::Observe(const char* aTopic,
     return NS_OK;
   }
 
-  if (!strcmp(aTopic, "low-disk-space")) {
-    if (mType == LocalStorage) {
-      mLowDiskSpace = true;
-    }
-
-    return NS_OK;
-  }
-
-  if (!strcmp(aTopic, "no-low-disk-space")) {
-    if (mType == LocalStorage) {
-      mLowDiskSpace = false;
-    }
-
-    return NS_OK;
-  }
-
 #ifdef DOM_STORAGE_TESTS
   if (!strcmp(aTopic, "test-reload")) {
     if (mType != LocalStorage) {
diff --git a/dom/storage/DOMStorageManager.h b/dom/storage/DOMStorageManager.h
index 666e16a6f..0bfd21975 100644
--- a/dom/storage/DOMStorageManager.h
+++ b/dom/storage/DOMStorageManager.h
@@ -102,12 +102,6 @@ private:
 
   const DOMStorage::StorageType mType;
 
-  // If mLowDiskSpace is true it indicates a low device storage situation and
-  // so no localStorage writes are allowed. sessionStorage writes are still
-  // allowed.
-  bool mLowDiskSpace;
-  bool IsLowDiskSpace() const { return mLowDiskSpace; };
-
   void ClearCaches(uint32_t aUnloadFlags,
                    const OriginAttributesPattern& aPattern,
                    const nsACString& aKeyPrefix);
diff --git a/dom/storage/DOMStorageObserver.cpp b/dom/storage/DOMStorageObserver.cpp
index a2b3f1da8..fbbab8e54 100644
--- a/dom/storage/DOMStorageObserver.cpp
+++ b/dom/storage/DOMStorageObserver.cpp
@@ -70,9 +70,6 @@ DOMStorageObserver::Init()
   obs->AddObserver(sSelf, "profile-before-change", true);
   obs->AddObserver(sSelf, "xpcom-shutdown", true);
 
-  // Observe low device storage notifications.
-  obs->AddObserver(sSelf, "disk-space-watcher", true);
-
 #ifdef DOM_STORAGE_TESTS
   // Testing
   obs->AddObserver(sSelf, "domstorage-test-flush-force", true);
@@ -313,16 +310,6 @@ DOMStorageObserver::Observe(nsISupports* aSubject,
     return NS_OK;
   }
 
-  if (!strcmp(aTopic, "disk-space-watcher")) {
-    if (NS_LITERAL_STRING("full").Equals(aData)) {
-      Notify("low-disk-space");
-    } else if (NS_LITERAL_STRING("free").Equals(aData)) {
-      Notify("no-low-disk-space");
-    }
-
-    return NS_OK;
-  }
-
 #ifdef DOM_STORAGE_TESTS
   if (!strcmp(aTopic, "domstorage-test-flush-force")) {
     DOMStorageDBBridge* db = DOMStorageCache::GetDatabase();
diff --git a/hal/Hal.cpp b/hal/Hal.cpp
index f88efd6cc..67930c355 100644
--- a/hal/Hal.cpp
+++ b/hal/Hal.cpp
@@ -855,22 +855,6 @@ void FactoryReset(mozilla::dom::FactoryResetReason& aReason)
   PROXY_IF_SANDBOXED(FactoryReset(aReason));
 }
 
-void
-StartDiskSpaceWatcher()
-{
-  AssertMainProcess();
-  AssertMainThread();
-  PROXY_IF_SANDBOXED(StartDiskSpaceWatcher());
-}
-
-void
-StopDiskSpaceWatcher()
-{
-  AssertMainProcess();
-  AssertMainThread();
-  PROXY_IF_SANDBOXED(StopDiskSpaceWatcher());
-}
-
 uint32_t
 GetTotalSystemMemory()
 {
diff --git a/hal/Hal.h b/hal/Hal.h
index 14247ee2e..5411b387a 100644
--- a/hal/Hal.h
+++ b/hal/Hal.h
@@ -477,20 +477,6 @@ void StartForceQuitWatchdog(hal::ShutdownMode aMode, int32_t aTimeoutSecs);
 void FactoryReset(mozilla::dom::FactoryResetReason& aReason);
 
 /**
- * Start monitoring disk space for low space situations.
- *
- * This API is currently only allowed to be used from the main process.
- */
-void StartDiskSpaceWatcher();
-
-/**
- * Stop monitoring disk space for low space situations.
- *
- * This API is currently only allowed to be used from the main process.
- */
-void StopDiskSpaceWatcher();
-
-/**
  * Get total system memory of device being run on in bytes.
  *
  * Returns 0 if we are unable to determine this information from /proc/meminfo.
diff --git a/hal/fallback/FallbackDiskSpaceWatcher.cpp b/hal/fallback/FallbackDiskSpaceWatcher.cpp
deleted file mode 100644
index 99d144397..000000000
--- a/hal/fallback/FallbackDiskSpaceWatcher.cpp
+++ /dev/null
@@ -1,19 +0,0 @@
-/* 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/. */
-
-namespace mozilla {
-namespace hal_impl {
-
-void
-StartDiskSpaceWatcher()
-{
-}
-
-void
-StopDiskSpaceWatcher()
-{
-}
-
-} // namespace hal_impl
-} // namespace mozilla
diff --git a/hal/moz.build b/hal/moz.build
index 3e1bae404..8d2950ac0 100644
--- a/hal/moz.build
+++ b/hal/moz.build
@@ -107,7 +107,6 @@ else:
     ]
 
 UNIFIED_SOURCES += [
-    'fallback/FallbackDiskSpaceWatcher.cpp',
     'fallback/FallbackFactoryReset.cpp',
     'fallback/FallbackProcessPriority.cpp',
     'fallback/FallbackScreenPower.cpp',
diff --git a/hal/sandbox/SandboxHal.cpp b/hal/sandbox/SandboxHal.cpp
index 5501d459b..aeaeb724e 100644
--- a/hal/sandbox/SandboxHal.cpp
+++ b/hal/sandbox/SandboxHal.cpp
@@ -352,18 +352,6 @@ FactoryReset(FactoryResetReason& aReason)
   }
 }
 
-void
-StartDiskSpaceWatcher()
-{
-  NS_RUNTIMEABORT("StartDiskSpaceWatcher() can't be called from sandboxed contexts.");
-}
-
-void
-StopDiskSpaceWatcher()
-{
-  NS_RUNTIMEABORT("StopDiskSpaceWatcher() can't be called from sandboxed contexts.");
-}
-
 bool IsHeadphoneEventFromInputDev()
 {
   NS_RUNTIMEABORT("IsHeadphoneEventFromInputDev() cannot be called from sandboxed contexts.");
diff --git a/toolkit/components/diskspacewatcher/DiskSpaceWatcher.cpp b/toolkit/components/diskspacewatcher/DiskSpaceWatcher.cpp
deleted file mode 100644
index 7f3b8cd08..000000000
--- a/toolkit/components/diskspacewatcher/DiskSpaceWatcher.cpp
+++ /dev/null
@@ -1,158 +0,0 @@
-/* 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 "DiskSpaceWatcher.h"
-#include "nsIObserverService.h"
-#include "nsXULAppAPI.h"
-#include "mozilla/Hal.h"
-#include "mozilla/ModuleUtils.h"
-#include "mozilla/Preferences.h"
-#include "mozilla/ClearOnShutdown.h"
-#include "mozilla/Services.h"
-
-#define NS_DISKSPACEWATCHER_CID \
-  { 0xab218518, 0xf197, 0x4fb4, { 0x8b, 0x0f, 0x8b, 0xb3, 0x4d, 0xf2, 0x4b, 0xf4 } }
-
-using namespace mozilla;
-
-StaticRefPtr<DiskSpaceWatcher> gDiskSpaceWatcher;
-
-NS_IMPL_ISUPPORTS(DiskSpaceWatcher, nsIDiskSpaceWatcher, nsIObserver)
-
-uint64_t DiskSpaceWatcher::sFreeSpace = 0;
-bool DiskSpaceWatcher::sIsDiskFull = false;
-
-DiskSpaceWatcher::DiskSpaceWatcher()
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  MOZ_ASSERT(!gDiskSpaceWatcher);
-}
-
-DiskSpaceWatcher::~DiskSpaceWatcher()
-{
-  MOZ_ASSERT(!gDiskSpaceWatcher);
-}
-
-already_AddRefed<DiskSpaceWatcher>
-DiskSpaceWatcher::FactoryCreate()
-{
-  if (!XRE_IsParentProcess()) {
-    return nullptr;
-  }
-
-  MOZ_ASSERT(NS_IsMainThread());
-
-  if (!Preferences::GetBool("disk_space_watcher.enabled", false)) {
-    return nullptr;
-  }
-
-  if (!gDiskSpaceWatcher) {
-    gDiskSpaceWatcher = new DiskSpaceWatcher();
-    ClearOnShutdown(&gDiskSpaceWatcher);
-  }
-
-  RefPtr<DiskSpaceWatcher> service = gDiskSpaceWatcher.get();
-  return service.forget();
-}
-
-NS_IMETHODIMP
-DiskSpaceWatcher::Observe(nsISupports* aSubject, const char* aTopic,
-                          const char16_t* aData)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-
-  if (!strcmp(aTopic, "profile-after-change")) {
-    nsCOMPtr<nsIObserverService> observerService =
-      mozilla::services::GetObserverService();
-    observerService->AddObserver(this, "profile-before-change", false);
-    mozilla::hal::StartDiskSpaceWatcher();
-    return NS_OK;
-  }
-
-  if (!strcmp(aTopic, "profile-before-change")) {
-    nsCOMPtr<nsIObserverService> observerService =
-      mozilla::services::GetObserverService();
-    observerService->RemoveObserver(this, "profile-before-change");
-    mozilla::hal::StopDiskSpaceWatcher();
-    return NS_OK;
-  }
-
-  MOZ_ASSERT(false, "DiskSpaceWatcher got unexpected topic!");
-  return NS_ERROR_UNEXPECTED;
-}
-
-NS_IMETHODIMP DiskSpaceWatcher::GetIsDiskFull(bool* aIsDiskFull)
-{
-  *aIsDiskFull = sIsDiskFull;
-  return NS_OK;
-}
-
-// GetFreeSpace is a macro on windows, and that messes up with the c++
-// compiler.
-#ifdef XP_WIN
-#undef GetFreeSpace
-#endif
-NS_IMETHODIMP DiskSpaceWatcher::GetFreeSpace(uint64_t* aFreeSpace)
-{
-  *aFreeSpace = sFreeSpace;
-  return NS_OK;
-}
-
-// static
-void DiskSpaceWatcher::UpdateState(bool aIsDiskFull, uint64_t aFreeSpace)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  if (!gDiskSpaceWatcher) {
-    return;
-  }
-
-  nsCOMPtr<nsIObserverService> observerService =
-    mozilla::services::GetObserverService();
-
-  sIsDiskFull = aIsDiskFull;
-  sFreeSpace = aFreeSpace;
-
-  if (!observerService) {
-    return;
-  }
-
-  const char16_t stateFull[] = { 'f', 'u', 'l', 'l', 0 };
-  const char16_t stateFree[] = { 'f', 'r', 'e', 'e', 0 };
-
-  nsCOMPtr<nsISupports> subject;
-  CallQueryInterface(gDiskSpaceWatcher.get(), getter_AddRefs(subject));
-  MOZ_ASSERT(subject);
-  observerService->NotifyObservers(subject,
-                                   DISKSPACEWATCHER_OBSERVER_TOPIC,
-                                   sIsDiskFull ? stateFull : stateFree);
-  return;
-}
-
-NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(DiskSpaceWatcher,
-                                         DiskSpaceWatcher::FactoryCreate)
-
-NS_DEFINE_NAMED_CID(NS_DISKSPACEWATCHER_CID);
-
-static const mozilla::Module::CIDEntry kDiskSpaceWatcherCIDs[] = {
-  { &kNS_DISKSPACEWATCHER_CID, false, nullptr, DiskSpaceWatcherConstructor },
-  { nullptr }
-};
-
-static const mozilla::Module::ContractIDEntry kDiskSpaceWatcherContracts[] = {
-  { "@mozilla.org/toolkit/disk-space-watcher;1", &kNS_DISKSPACEWATCHER_CID },
-  { nullptr }
-};
-
-static const mozilla::Module::CategoryEntry kDiskSpaceWatcherCategories[] = {
-  { nullptr }
-};
-
-static const mozilla::Module kDiskSpaceWatcherModule = {
-  mozilla::Module::kVersion,
-  kDiskSpaceWatcherCIDs,
-  kDiskSpaceWatcherContracts,
-  kDiskSpaceWatcherCategories
-};
-
-NSMODULE_DEFN(DiskSpaceWatcherModule) = &kDiskSpaceWatcherModule;
diff --git a/toolkit/components/diskspacewatcher/DiskSpaceWatcher.h b/toolkit/components/diskspacewatcher/DiskSpaceWatcher.h
deleted file mode 100644
index 6559af3cd..000000000
--- a/toolkit/components/diskspacewatcher/DiskSpaceWatcher.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/* 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/. */
-
-#ifndef __DISKSPACEWATCHER_H__
-
-#include "nsIDiskSpaceWatcher.h"
-#include "nsIObserver.h"
-#include "nsCOMPtr.h"
-
-class DiskSpaceWatcher final : public nsIDiskSpaceWatcher,
-                               public nsIObserver
-{
-public:
-  NS_DECL_ISUPPORTS
-  NS_DECL_NSIDISKSPACEWATCHER
-  NS_DECL_NSIOBSERVER
-
-  static already_AddRefed<DiskSpaceWatcher>
-  FactoryCreate();
-
-  static void UpdateState(bool aIsDiskFull, uint64_t aFreeSpace);
-
-private:
-  DiskSpaceWatcher();
-  ~DiskSpaceWatcher();
-
-  static uint64_t sFreeSpace;
-  static bool     sIsDiskFull;
-};
-
-#endif // __DISKSPACEWATCHER_H__
diff --git a/toolkit/components/diskspacewatcher/moz.build b/toolkit/components/diskspacewatcher/moz.build
deleted file mode 100644
index 168af46a6..000000000
--- a/toolkit/components/diskspacewatcher/moz.build
+++ /dev/null
@@ -1,23 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# 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/.
-
-XPIDL_SOURCES += [
-    'nsIDiskSpaceWatcher.idl',
-]
-
-EXPORTS += [
-    'DiskSpaceWatcher.h'
-]
-
-XPIDL_MODULE = 'diskspacewatcher'
-
-SOURCES = [
-    'DiskSpaceWatcher.cpp',
-]
-
-include('/ipc/chromium/chromium-config.mozbuild')
-
-FINAL_LIBRARY = 'xul'
diff --git a/toolkit/components/diskspacewatcher/nsIDiskSpaceWatcher.idl b/toolkit/components/diskspacewatcher/nsIDiskSpaceWatcher.idl
deleted file mode 100644
index a9c60ca9f..000000000
--- a/toolkit/components/diskspacewatcher/nsIDiskSpaceWatcher.idl
+++ /dev/null
@@ -1,25 +0,0 @@
-/* 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 "nsISupports.idl"
-
-%{ C++
-#ifdef XP_WIN
-#undef GetFreeSpace
-#endif
-%}
-
-[scriptable, uuid(3aceba74-2ed5-4e99-8fe4-06e90e2b8ef0)]
-interface nsIDiskSpaceWatcher : nsISupports
-{
-  readonly attribute bool isDiskFull; // True if we are low on disk space.
-  readonly attribute unsigned long long freeSpace; // The free space currently available.
-};
-
-%{ C++
-#define DISKSPACEWATCHER_CONTRACTID "@mozilla.org/toolkit/disk-space-watcher;1"
-
-// The data for this notification will be either 'free' or 'full'.
-#define DISKSPACEWATCHER_OBSERVER_TOPIC "disk-space-watcher"
-%}
diff --git a/toolkit/components/moz.build b/toolkit/components/moz.build
index 3f17bfb6d..d9dae12d1 100644
--- a/toolkit/components/moz.build
+++ b/toolkit/components/moz.build
@@ -24,7 +24,6 @@ DIRS += [
     'contextualidentity',
     'cookie',
     'crashmonitor',
-    'diskspacewatcher',
     'downloads',
     'exthelper',
     'filewatcher',
diff --git a/uriloader/prefetch/nsOfflineCacheUpdate.h b/uriloader/prefetch/nsOfflineCacheUpdate.h
index 4ccba4135..2e6d6d30c 100644
--- a/uriloader/prefetch/nsOfflineCacheUpdate.h
+++ b/uriloader/prefetch/nsOfflineCacheUpdate.h
@@ -375,7 +375,6 @@ private:
 
     bool mDisabled;
     bool mUpdateRunning;
-    bool mLowFreeSpace;
 };
 
 #endif
diff --git a/uriloader/prefetch/nsOfflineCacheUpdateService.cpp b/uriloader/prefetch/nsOfflineCacheUpdateService.cpp
index adb3fd516..6a67af013 100644
--- a/uriloader/prefetch/nsOfflineCacheUpdateService.cpp
+++ b/uriloader/prefetch/nsOfflineCacheUpdateService.cpp
@@ -39,7 +39,6 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/Unused.h"
-#include "nsIDiskSpaceWatcher.h"
 #include "nsIDocShell.h"
 #include "nsIDocShellTreeItem.h"
 #include "nsIDocShellTreeOwner.h"
@@ -246,7 +245,6 @@ NS_IMPL_ISUPPORTS(nsOfflineCacheUpdateService,
 nsOfflineCacheUpdateService::nsOfflineCacheUpdateService()
     : mDisabled(false)
     , mUpdateRunning(false)
-    , mLowFreeSpace(false)
 {
     MOZ_ASSERT(NS_IsMainThread());
     Preferences::AddBoolVarCache(&sAllowOfflineCache,
@@ -273,19 +271,6 @@ nsOfflineCacheUpdateService::Init()
                                                true);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    // Get the current status of the disk in terms of free space and observe
-    // low device storage notifications.
-    nsCOMPtr<nsIDiskSpaceWatcher> diskSpaceWatcherService =
-      do_GetService("@mozilla.org/toolkit/disk-space-watcher;1");
-    if (diskSpaceWatcherService) {
-      diskSpaceWatcherService->GetIsDiskFull(&mLowFreeSpace);
-    } else {
-      NS_WARNING("Could not get disk status from nsIDiskSpaceWatcher");
-    }
-
-    rv = observerService->AddObserver(this, "disk-space-watcher", false);
-    NS_ENSURE_SUCCESS(rv, rv);
-
     gOfflineCacheUpdateService = this;
 
     return NS_OK;
@@ -407,11 +392,7 @@ nsOfflineCacheUpdateService::ProcessNextUpdate()
 
     if (mUpdates.Length() > 0) {
         mUpdateRunning = true;
-        // Canceling the update before Begin() call will make the update
-        // asynchronously finish with an error.
-        if (mLowFreeSpace) {
-            mUpdates[0]->Cancel();
-        }
+
         return mUpdates[0]->Begin();
     }
 
@@ -582,17 +563,6 @@ nsOfflineCacheUpdateService::Observe(nsISupports     *aSubject,
         mDisabled = true;
     }
 
-    if (!strcmp(aTopic, "disk-space-watcher")) {
-        if (NS_LITERAL_STRING("full").Equals(aData)) {
-            mLowFreeSpace = true;
-            for (uint32_t i = 0; i < mUpdates.Length(); i++) {
-                mUpdates[i]->Cancel();
-            }
-        } else if (NS_LITERAL_STRING("free").Equals(aData)) {
-            mLowFreeSpace = false;
-        }
-    }
-
     return NS_OK;
 }