Remove command buffer sample app support.

include/views/SkOSWindow_SDL.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkOSWindow_SDL_DEFINED
 #define SkOSWindow_SDL_DEFINED
 
 #include "SDL.h"
 #include "SDL_opengl.h"
 #include "SkWindow.h"
 
 class SkOSWindow : public SkWindow {
 public:
     SkOSWindow(void*);
     virtual ~SkOSWindow();
 
     enum SkBackEndTypes {
         kNone_BackEndType, // TODO: remove this, it's not a real option.
         kNativeGL_BackEndType,
 #if SK_ANGLE
         kANGLE_BackEndType,
 #endif // SK_ANGLE
-#if SK_COMMAND_BUFFER
-        kCommandBuffer_BackEndType,
-#endif // SK_COMMAND_BUFFER
     };
 
     void release();
     bool attach(SkBackEndTypes attachType, int msaaSampleCount, bool deepColor, AttachmentInfo*);
     void present();
     bool makeFullscreen();
     void setVsync(bool);
     void closeWindow();
     static void RunEventLoop();
 
 protected:
     void onSetTitle(const char title[]) override;
 
 private:
     void createWindow(int msaaSampleCount);
     void destroyWindow();
     void updateWindowTitle();
     static SkOSWindow* GetInstanceForWindowID(Uint32 windowID);
     static bool HasDirtyWindows();
     static void UpdateDirtyWindows();
     static void HandleEvent(const SDL_Event&);
 
     SDL_Window* fWindow;
     SDL_GLContext fGLContext;
     int fWindowMSAASampleCount;
     typedef SkWindow INHERITED;
 };
 
 #endif