[DevTools] Handle emulated device scale factor and original device scale factor properly.

content/renderer/devtools/render_widget_screen_metrics_emulator.h

 // Copyright 2016 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.
 
 #ifndef CONTENT_RENDERER_DEVTOOLS_RENDER_WIDGET_SCREEN_METRICS_EMULATOR_H_
 #define CONTENT_RENDERER_DEVTOOLS_RENDER_WIDGET_SCREEN_METRICS_EMULATOR_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "content/common/resize_params.h"
 #include "third_party/WebKit/public/web/WebDeviceEmulationParams.h"
@@ skipping 41 matching lines @@
   void ChangeEmulationParams(const blink::WebDeviceEmulationParams& params);
 
   // The following methods alter handlers' behavior for messages related to
   // widget size and position.
   void OnResize(const ResizeParams& params);
   void OnUpdateScreenRects(const gfx::Rect& view_screen_rect,
                            const gfx::Rect& window_screen_rect);
   void OnShowContextMenu(ContextMenuParams* params);
   gfx::Rect AdjustValidationMessageAnchor(const gfx::Rect& anchor);
 
- private:
-  // Apply original_resize_params_
+  // Apply parameters to the render widget.
   void Apply();
 
+ private:
   RenderWidgetScreenMetricsEmulatorDelegate* const delegate_;
 
   // Parameters as passed by RenderWidget::EnableScreenMetricsEmulation.
   blink::WebDeviceEmulationParams emulation_params_;
 
   // The computed scale and offset used to fit widget into browser window.
   float scale_;
   gfx::PointF offset_;
 
   // Widget rect as passed to webwidget.
   gfx::Rect applied_widget_rect_;
 
   // Original values to restore back after emulation ends.
   ResizeParams original_resize_params_;
   gfx::Rect original_view_screen_rect_;
   gfx::Rect original_window_screen_rect_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetScreenMetricsEmulator);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_DEVTOOLS_RENDER_WIDGET_SCREEN_METRICS_EMULATOR_H_