[Android] Use SetTransformOrigin for glow-effect layers

content/browser/android/edge_effect.cc

 // Copyright (c) 2013 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.
 
 #include "content/browser/android/edge_effect.h"
 
 #include "cc/layers/layer.h"
 
 namespace content {
 
@@ skipping 115 matching lines @@
 }
 
 void UpdateLayer(cc::Layer* layer,
                  EdgeEffect::Edge edge,
                  const gfx::SizeF& window_size,
                  int offset,
                  int height,
                  float opacity) {
   DCHECK(layer);
   layer->SetIsDrawable(true);
+  gfx::Size bounds = ComputeBounds(edge, window_size, height);
+  layer->SetTransformOrigin(
+      gfx::Point3F(bounds.width() * 0.5f, bounds.height() * 0.5f, 0));
   layer->SetTransform(ComputeTransform(edge, window_size, offset, height));
-  layer->SetBounds(ComputeBounds(edge, window_size, height));
+  layer->SetBounds(bounds);
   layer->SetOpacity(Clamp(opacity, 0.f, 1.f));
 }
 
 } // namespace
 
 EdgeEffect::EdgeEffect(scoped_refptr<cc::Layer> edge,
                        scoped_refptr<cc::Layer> glow)
   : edge_(edge)
   , glow_(glow)
   , edge_alpha_(0)
@@ skipping 220 matching lines @@
   UpdateLayer(
       glow_.get(), edge, window_size, offset, scaled_glow_height, glow_alpha_);
 
   // Edge
  const int scaled_edge_height = static_cast<int>(edge_height * edge_scale_y_);
   UpdateLayer(
       edge_.get(), edge, window_size, offset, scaled_edge_height, edge_alpha_);
 }
 
 } // namespace content