Handle app custom icon via aura::Window property.

components/exo/shell_surface.h

 // Copyright 2015 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 COMPONENTS_EXO_SHELL_SURFACE_H_
 #define COMPONENTS_EXO_SHELL_SURFACE_H_
 
 #include <cstdint>
 #include <deque>
 #include <memory>
@@ skipping 136 matching lines @@
   void SetSystemModal(bool system_modal);
 
   // Sets the application ID for the window. The application ID identifies the
   // general class of applications to which the window belongs.
   static void SetApplicationId(aura::Window* window, const std::string& id);
   static const std::string* GetApplicationId(aura::Window* window);
 
   // Set the application ID for the surface.
   void SetApplicationId(const std::string& application_id);
 
+  // Set icon for the surface.
+  void SetAppIcon(const gfx::ImageSkia& icon);

[reveman, 2017/06/01 22:05:36]

nit: SetIcon or SetApplicationIcon as we're not using the App abbreviation
above. I prefer SetIcon as it's consistent with SetTitle.

[khmel, 2017/06/01 22:19:27]

Done.

+
   // Start an interactive move of surface.
   void Move();
 
   // Start an interactive resize of surface. |component| is one of the windows
   // HT constants (see ui/base/hit_test.h) and describes in what direction the
   // surface should be resized.
   void Resize(int component);
 
   // Signal a request to close the window. It is up to the implementation to
   // actually decide to do so though.
@@ skipping 53 matching lines @@
   bool IsSurfaceSynchronized() const override;
 
   // Overridden from SurfaceObserver:
   void OnSurfaceDestroying(Surface* surface) override;
 
   // Overridden from views::WidgetDelegate:
   bool CanResize() const override;
   bool CanMaximize() const override;
   bool CanMinimize() const override;
   base::string16 GetWindowTitle() const override;
+  gfx::ImageSkia GetWindowIcon() override;
   void SaveWindowPlacement(const gfx::Rect& bounds,
                            ui::WindowShowState show_state) override;
   bool GetSavedWindowPlacement(const views::Widget* widget,
                                gfx::Rect* bounds,
                                ui::WindowShowState* show_state) const override;
   void WindowClosing() override;
   views::Widget* GetWidget() override;
   const views::Widget* GetWidget() const override;
   views::View* GetContentsView() override;
   views::NonClientFrameView* CreateNonClientFrameView(
@@ skipping 126 matching lines @@
   gfx::Rect shadow_content_bounds_;
   float shadow_background_opacity_ = 1.0;
   std::deque<Config> pending_configs_;
   std::unique_ptr<ash::WindowResizer> resizer_;
   std::unique_ptr<ScopedAnimationsDisabled> scoped_animations_disabled_;
   int top_inset_height_ = 0;
   int pending_top_inset_height_ = 0;
   bool shadow_underlay_in_surface_ = true;
   bool pending_shadow_underlay_in_surface_ = true;
   bool system_modal_ = false;
+  gfx::ImageSkia icon_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellSurface);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_SHELL_SURFACE_H_