Bug 1379448 - ContentCacheInParent::FlushPendingNotifications() should do nothing if aWidget is nullptr r=m_kato

Due to the fix of bug 1376424, ContentCacheInParent::FlushPendingNotifications() may be called when aWidget is nullptr. In this case, it doesn't need to do anything.  So, it should ignore the call.

MozReview-Commit-ID: Fj3J76v6Xuk

--HG--
extra : rebase_source : 18c722628a3ae8fa50beca3908d5e732cec404d9

widget/ContentCache.cpp

@@ -1351,28 +1351,34 @@ ContentCacheInParent::FlushPendingNotifications(nsIWidget* aWidget)
 {
   MOZ_ASSERT(!mPendingEventsNeedingAck);
 
+  // If the TabParent's widget has already gone, this can do nothing since
+  // widget is necessary to notify IME of something.
+  if (!aWidget) {
+    return;
+  }
+
   // New notifications which are notified during flushing pending notifications
   // should be merged again.
   mPendingEventsNeedingAck++;
 
-  nsCOMPtr<nsIWidget> kungFuDeathGrip(aWidget);
+  nsCOMPtr<nsIWidget> widget = aWidget;
 
   // First, text change notification should be sent because selection change
   // notification notifies IME of current selection range in the latest content.
   // So, IME may need the latest content before that.
   if (mPendingTextChange.HasNotification()) {
     IMENotification notification(mPendingTextChange);
-    if (!aWidget->Destroyed()) {
+    if (!widget->Destroyed()) {
       mPendingTextChange.Clear();
-      IMEStateManager::NotifyIME(notification, aWidget, &mTabParent);
+      IMEStateManager::NotifyIME(notification, widget, &mTabParent);
     }
   }
 
   if (mPendingSelectionChange.HasNotification()) {
     IMENotification notification(mPendingSelectionChange);
-    if (!aWidget->Destroyed()) {
+    if (!widget->Destroyed()) {
       mPendingSelectionChange.Clear();
-      IMEStateManager::NotifyIME(notification, aWidget, &mTabParent);
+      IMEStateManager::NotifyIME(notification, widget, &mTabParent);
     }
   }
 
@@ -1380,9 +1386,9 @@ ContentCacheInParent::FlushPendingNotifications(nsIWidget* aWidget)
   // notification because IME may want to query position of new caret position.
   if (mPendingLayoutChange.HasNotification()) {
     IMENotification notification(mPendingLayoutChange);
-    if (!aWidget->Destroyed()) {
+    if (!widget->Destroyed()) {
       mPendingLayoutChange.Clear();
-      IMEStateManager::NotifyIME(notification, aWidget, &mTabParent);
+      IMEStateManager::NotifyIME(notification, widget, &mTabParent);
     }
   }
 
@@ -1390,18 +1396,18 @@ ContentCacheInParent::FlushPendingNotifications(nsIWidget* aWidget)
   // finishing handling whole sending events.
   if (mPendingCompositionUpdate.HasNotification()) {
     IMENotification notification(mPendingCompositionUpdate);
-    if (!aWidget->Destroyed()) {
+    if (!widget->Destroyed()) {
       mPendingCompositionUpdate.Clear();
-      IMEStateManager::NotifyIME(notification, aWidget, &mTabParent);
+      IMEStateManager::NotifyIME(notification, widget, &mTabParent);
     }
   }
 
-  if (!--mPendingEventsNeedingAck && !aWidget->Destroyed() &&
+  if (!--mPendingEventsNeedingAck && !widget->Destroyed() &&
       (mPendingTextChange.HasNotification() ||
        mPendingSelectionChange.HasNotification() ||
        mPendingLayoutChange.HasNotification() ||
        mPendingCompositionUpdate.HasNotification())) {
-    FlushPendingNotifications(aWidget);
+    FlushPendingNotifications(widget);
   }
 }