ui: Make gfx::Size::Scale() mutate the class. Add gfx::ScaleSize() similar to Rect/Point.

ui/compositor/layer.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.
 
 #include "ui/compositor/layer.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 749 matching lines @@
   DCHECK(web_layer_);
   bool should_draw = type_ != LAYER_NOT_DRAWN;
   if (!web_layer_is_accelerated_) {
     if (type_ != LAYER_SOLID_COLOR) {
       web_layer_->setDrawsContent(should_draw);
     }
     web_layer_->setBounds(ConvertSizeToPixel(this, bounds_.size()));
   } else {
     DCHECK(texture_);
 
+    float texture_scale_factor = 1.0f / texture_->device_scale_factor();
     gfx::Size texture_size = gfx::ToFlooredSize(
-          texture_->size().Scale(1.0f / texture_->device_scale_factor()));
+        gfx::ScaleSize(texture_->size(), texture_scale_factor));
 
     gfx::Size size(std::min(bounds().width(), texture_size.width()),
                    std::min(bounds().height(), texture_size.height()));
     WebKit::WebFloatRect rect(
         0,
         0,
         static_cast<float>(size.width())/texture_size.width(),
         static_cast<float>(size.height())/texture_size.height());
     texture_layer_->setUVRect(rect);
 
     gfx::Size size_in_pixel = ConvertSizeToPixel(this, size);
     web_layer_->setBounds(size_in_pixel);
   }
 }
 
 void Layer::RecomputeDebugBorderColor() {
   if (!show_debug_borders_)
     return;
   unsigned int color = 0xFF000000;
   color |= web_layer_is_accelerated_ ? 0x0000FF00 : 0x00FF0000;
   bool opaque = fills_bounds_opaquely_ && (GetCombinedOpacity() == 1.f);
   if (!opaque)
     color |= 0xFF;
   web_layer_->setDebugBorderColor(color);
 }
 
 }  // namespace ui