Bug 1163212 - The resize event should not be cancelable. r=smaug

--HG--
extra : rebase_source : aef9af37dc8a1fdcc481ad9a69e4bf59a5e7a2bb

widget/BasicEvents.h

@@ -314,7 +314,11 @@ private:
         mFlags.mBubbles = true;
         break;
       default:
-        mFlags.mCancelable = true;
+        if (mMessage == eResize) {
+          mFlags.mCancelable = false;
+        } else {
+          mFlags.mCancelable = true;
+        }
         mFlags.mBubbles = true;
         break;
     }