Bug 1239589 - Change nsBaseWidget::mBounds to a LayoutDeviceIntRect. r=kats.

This patch removes dozens of ToUnknown/FromUnknown conversions and doesn't add
any new ones, which is nice. It also removes UntypedDevPixelsToCocoaPoints(),
which is no longer needed.

widget/PluginWidgetProxy.cpp

@@ -64,7 +64,7 @@ PluginWidgetProxy::Create(nsIWidget* aParent,
 
   BaseCreate(aParent, aInitData);
 
-  mBounds = aRect.ToUnknownRect();
+  mBounds = aRect;
   mEnabled = true;
   mVisible = true;