views: Early out of painting Views with empty bounds.

ui/views/view.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
@@ skipping 719 matching lines @@
   } else if (parent_) {
     // Translate the requested paint rect to the parent's coordinate system
     // then pass this notification up to the parent.
     parent_->SchedulePaintInRect(ConvertRectToParent(rect));
   }
 }
 
 void View::Paint(const ui::PaintContext& parent_context) {
   if (!visible_)
     return;
+  if (bounds().IsEmpty())

[weiliangc, 2015/06/09 22:04:42]

nit: We can use size() instead?

[danakj, 2015/06/09 22:05:15]

Ya, though size() is bounds().size() so that's an extra indirection which is how
I ended up here.

+    return;
 
   gfx::Vector2d offset_to_parent;
   if (!layer()) {
     // If the View has a layer() then it is a paint root. Otherwise, we need to
     // add the offset from the parent into the total offset from the paint root.
     DCHECK_IMPLIES(!parent(), bounds().origin() == gfx::Point());
     offset_to_parent = GetMirroredPosition().OffsetFromOrigin();
   }
   ui::PaintContext context(parent_context, offset_to_parent);
 
@@ skipping 1618 matching lines @@
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   widget->RunShellDrag(this, data, widget_location, drag_operations, source);
   // WARNING: we may have been deleted.
   return true;
 }
 
 }  // namespace views