Mus Demo: Move definition of WindowTreeData into separate files.

services/ui/demo/mus_demo.h

Index: services/ui/demo/mus_demo.h
diff --git a/services/ui/demo/mus_demo.h b/services/ui/demo/mus_demo.h
index 55112dadbc22d512d8e755a09b804ba9e90ddb24..a881deccbaa504239f285b0b7989d7ed459ef263 100644
--- a/services/ui/demo/mus_demo.h
+++ b/services/ui/demo/mus_demo.h
@@ -28,6 +28,10 @@ class DefaultCaptureClient;
 }
 }  // namespace aura
 
+namespace aura_extra {
+class ImageWindowDelegate;
+}  // namespace aura_extra
+
 namespace wm {
 class WMState;
 }
@@ -46,6 +50,43 @@ class MusDemo : public service_manager::Service,
   MusDemo();
   ~MusDemo() override;
 
+ protected:
+  class WindowTreeData {

[kylechar, 2017/02/14 16:58:10]

This is a pretty big class. Is there any reason it can't go in it's own file?

[fwang, 2017/02/14 17:20:26]

I guess so. I was not sure either :-)

[fwang, 2017/02/15 13:45:06]

Done.

+   public:
+    explicit WindowTreeData(
+        std::unique_ptr<aura::WindowTreeHostMus> window_tree_host,
+        int square_size);
+    ~WindowTreeData();
+
+   private:
+    // Initializes the window tree host and start drawing frames.
+    void Init(std::unique_ptr<aura::WindowTreeHostMus> window_tree_host);
+
+    // Draws one frame, incrementing the rotation angle.
+    void DrawFrame();
+
+    // Helper function to retrieve the window to which we draw the bitmap.
+    aura::Window* bitmap_window();
+
+    // The Window tree host corresponding to this data.
+    std::unique_ptr<aura::WindowTreeHostMus> window_tree_host_;
+
+    // Destroys itself when the window gets destroyed.
+    aura_extra::ImageWindowDelegate* window_delegate_ = nullptr;
+
+    // Timer for calling DrawFrame().
+    base::RepeatingTimer timer_;
+
+    // Current rotation angle for drawing.
+    double angle_ = 0.0;
+
+    // Size in pixels of the square to draw.
+    const int square_size_;
+
+    DISALLOW_COPY_AND_ASSIGN(WindowTreeData);
+  };
+  std::unique_ptr<WindowTreeData> window_tree_data_;

[kylechar, 2017/02/14 16:58:10]

Move to private section.

[fwang, 2017/02/14 17:20:26]

Yes, this will be needed later (see https://codereview.chromium.org/2693923004/
and https://codereview.chromium.org/2622103004/) but I did this move in that
commit as it was more logical.

[kylechar, 2017/02/14 18:27:00]

It should be in the private section regardless. If a subclass needs to use it
then a protected accessor method can be added.

https://google.github.io/styleguide/cppguide.html#Access_Control

[fwang, 2017/02/15 13:45:06]

Done.

+
  private:
   // service_manager::Service:
   void OnStart() override;
@@ -102,9 +143,6 @@ class MusDemo : public service_manager::Service,
   std::unique_ptr<::wm::WMState> wm_state_;
   std::unique_ptr<aura::PropertyConverter> property_converter_;
 
-  class WindowTreeData;
-  std::unique_ptr<WindowTreeData> window_tree_data_;
-
   DISALLOW_COPY_AND_ASSIGN(MusDemo);
 };