Convert SetVisuallyDeemphasized IPC to mojo

extensions/renderer/extensions_render_frame_observer.h

 // Copyright 2014 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 EXTENSIONS_RENDERER_EXTENSIONS_RENDER_FRAME_OBSERVER_H_
 #define EXTENSIONS_RENDERER_EXTENSIONS_RENDER_FRAME_OBSERVER_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "content/public/renderer/render_frame_observer.h"
+#include "extensions/common/mojo/app_window_handler.mojom.h"
+#include "mojo/public/cpp/bindings/binding_set.h"
 
 namespace extensions {
 
 // This class holds the extensions specific parts of RenderFrame, and has the
 // same lifetime.
-class ExtensionsRenderFrameObserver
-    : public content::RenderFrameObserver {
+class ExtensionsRenderFrameObserver : public content::RenderFrameObserver,
+                                      public mojom::AppWindowHandler {
  public:
   explicit ExtensionsRenderFrameObserver(
       content::RenderFrame* render_frame);
   ~ExtensionsRenderFrameObserver() override;
 
  private:
+  void AssociateBindings(mojom::AppWindowHandlerRequest request);
+
+  // Toggles visual muting of the render view area. This is on when a
+  // constrained window is showing.
+  void SetVisuallyDeemphasized(bool deemphasized) override;
+
   // RenderFrameObserver implementation.
   void DetailedConsoleMessageAdded(const base::string16& message,
                                    const base::string16& source,
                                    const base::string16& stack_trace,
                                    uint32_t line_number,
                                    int32_t severity_level) override;
   void OnDestruct() override;
 
+  // true if webview is overlayed with grey color.
+  bool webview_visually_deemphasized_;

[Ken Rockot(use gerrit already), 2017/03/08 17:31:38]

optional (personal preference) nit: you could initialize this here instead of in
the constructor definition.

[catmullings, 2017/03/08 18:23:00]

I'll leave this as it is.

+
+  mojo::BindingSet<mojom::AppWindowHandler> bindings_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionsRenderFrameObserver);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_EXTENSIONS_RENDER_FRAME_OBSERVER_H_