Bug 836786 - Allow mousemove events to propagate from windowless plugins. r=josh

dom/plugins/base/nsPluginInstanceOwner.cpp

@@ -1682,7 +1682,8 @@ nsPluginInstanceOwner::ProcessMouseDown(nsIDOMEvent* aMouseEvent)
   return NS_OK;
 }
 
-nsresult nsPluginInstanceOwner::DispatchMouseToPlugin(nsIDOMEvent* aMouseEvent)
+nsresult nsPluginInstanceOwner::DispatchMouseToPlugin(nsIDOMEvent* aMouseEvent,
+                                                      bool aAllowPropagate)
 {
 #if !defined(XP_MACOSX)
   if (!mPluginWindow || (mPluginWindow->type == NPWindowTypeWindow))
@@ -1699,7 +1700,9 @@ nsresult nsPluginInstanceOwner::DispatchMouseToPlugin(nsIDOMEvent* aMouseEvent)
     nsEventStatus rv = ProcessEvent(*mouseEvent);
     if (nsEventStatus_eConsumeNoDefault == rv) {
       aMouseEvent->PreventDefault();
-      aMouseEvent->StopPropagation();
+      if (!aAllowPropagate) {
+        aMouseEvent->StopPropagation();
+      }
     }
     if (mouseEvent->message == NS_MOUSE_BUTTON_UP) {
       mLastMouseDownButtonType = -1;
@@ -1741,8 +1744,10 @@ nsPluginInstanceOwner::HandleEvent(nsIDOMEvent* aEvent)
     }
     return DispatchMouseToPlugin(aEvent);
   }
-  if (eventType.EqualsLiteral("mousemove") ||
-      eventType.EqualsLiteral("click") ||
+  if (eventType.EqualsLiteral("mousemove")) {
+    return DispatchMouseToPlugin(aEvent, true);
+  }
+  if (eventType.EqualsLiteral("click") ||
       eventType.EqualsLiteral("dblclick") ||
       eventType.EqualsLiteral("mouseover") ||
       eventType.EqualsLiteral("mouseout")) {

dom/plugins/base/nsPluginInstanceOwner.h

@@ -365,7 +365,8 @@ private:
   nsRefPtr<nsPluginDOMContextMenuListener> mCXMenuListener;
   
   nsresult DispatchKeyToPlugin(nsIDOMEvent* aKeyEvent);
-  nsresult DispatchMouseToPlugin(nsIDOMEvent* aMouseEvent);
+  nsresult DispatchMouseToPlugin(nsIDOMEvent* aMouseEvent,
+                                 bool aAllowPropagate = false);
   nsresult DispatchFocusToPlugin(nsIDOMEvent* aFocusEvent);
 
   int mLastMouseDownButtonType;