Bug 814822 - Notify wake lock change when content crashes. r=jlebar

hal/HalWakeLock.cpp

@@ -53,17 +53,6 @@ static StaticAutoPtr<LockTable> sLockTable;
 static bool sInitialized = false;
 static bool sIsShuttingDown = false;
 
-static PLDHashOperator
-RemoveChildFromList(const nsAString& aKey, ProcessLockTable* aTable, void* aUserArg)
-{
-  MOZ_ASSERT(aUserArg);
-
-  uint64_t childID = *static_cast<uint64_t*>(aUserArg);
-  aTable->Remove(childID);
-
-  return PL_DHASH_NEXT;
-}
-
 static PLDHashOperator
 CountWakeLocks(const uint64_t& aKey, LockCount aCount, void* aUserArg)
 {
@@ -76,6 +65,31 @@ CountWakeLocks(const uint64_t& aKey, LockCount aCount, void* aUserArg)
   return PL_DHASH_NEXT;
 }
 
+static PLDHashOperator
+RemoveChildFromList(const nsAString& aKey, ProcessLockTable* aTable, void* aUserArg)
+{
+  MOZ_ASSERT(aUserArg);
+
+  uint64_t childID = *static_cast<uint64_t*>(aUserArg);
+  if (aTable->Get(childID, NULL)) {
+    aTable->Remove(childID);
+    if (sActiveListeners) {
+      LockCount totalCount;
+      WakeLockInformation info;
+      aTable->EnumerateRead(CountWakeLocks, &totalCount);
+      if (!totalCount.numLocks) {
+        sLockTable->Remove(aKey);
+      }
+      info.numLocks() = totalCount.numLocks;
+      info.numHidden() = totalCount.numHidden;
+      info.topic() = aKey;
+      NotifyWakeLockChange(info);
+    }
+  }
+
+  return PL_DHASH_NEXT;
+}
+
 class ClearHashtableOnShutdown MOZ_FINAL : public nsIObserver {
 public:
   NS_DECL_ISUPPORTS
@@ -162,6 +176,8 @@ ModifyWakeLockInternal(const nsAString& aTopic,
                        hal::WakeLockControl aHiddenAdjust,
                        uint64_t aProcessID)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+
   if (sIsShuttingDown) {
     return;
   }