Added FakeGlVideoDecodeEngine to exercise the IPC protocol for hardware video decoding

chrome/renderer/media/gles2_video_decode_context.h

 // Copyright (c) 2010 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 CHROME_RENDERER_MEDIA_GLES2_VIDEO_DECODE_CONTEXT_H_
 #define CHROME_RENDERER_MEDIA_GLES2_VIDEO_DECODE_CONTEXT_H_
 
+#include "base/message_loop.h"
 #include "media/video/video_decode_context.h"
 
-namespace WebKit {
-class WebGLES2Context;
-}  // namespace WebKit
+namespace ggl {
+class Context;
+}  // namespace ggl
 
 // FUNCTIONS
 //
-// This is a class that provides a video decode context using a GLES2 backend.
-// It provides resources for a VideoDecodeEngine to store decoded video frames
-// in the GLES2 context.
+// This is a class that provides a video decode context using a ggl::Context
+// backend.
+//
+// It provides resources for a VideoDecodeEngine to store decoded video frames.
 //
 // This class is aware of the command buffer implementation of GLES2 inside the
 // Chrome renderer and keeps a reference of ggl::Context. It might use GLES2
 // commands specific to Chrome's renderer process to provide needed resources.
 //
 // There are two different kinds of video frame storage provided by this class:
 // 1. Memory mapped YUV textures (aka software decoding mode).
 //    Each video frame allocated is backed by 3 luminance textures carrying
 //    the Y, U and V planes.
 //
@@ skipping 14 matching lines @@
 //
 // 2. RGBA texture (aka hardware decoding mode).
 //    In this mode of operation each video frame is backed by a RGBA texture.
 //    This is used only when hardware video decoding is used. The texture needs
 //    to be generated and allocated inside the renderer process first. This
 //    will establish a translation between texture ID in the renderer process
 //    and the GPU process.
 //
 //    The texture ID generated is used by IpcVideoDecodeEngine only to be sent
 //    the GPU process. Inside the GPU process the texture ID is translated to
-//    a real texture ID inside the actual GLES context. The real texture ID is
-//    then assigned to the hardware video decoder for storing the video frame.
+//    a real texture ID inside the actual context. The real texture ID is then
+//    assigned to the hardware video decoder for storing the video frame.
 //
 //    WebKit will see the video frame as a normal RGBA texture and perform
 //    necessary render operations.
 //
 // In both operation modes, the objective is to have WebKit see the video frames
 // as regular textures.
 //
 // THREAD SEMANTICS
 //
 // This class is accessed on two threads, namely the Render Thread and the
@@ skipping 11 matching lines @@
     // only in software decoding mode.
     kMemoryMappedYuvTextures,
 
     // This video decode context provides RBGA textures as storage. This is
     // used in hardware decoding mode.
     kRgbaTextures,
   };
 
   //--------------------------------------------------------------------------
   // Render Thread
-  Gles2VideoDecodeContext(StorageType type,
-                          WebKit::WebGLES2Context* gles2context);
+  Gles2VideoDecodeContext(StorageType type, ggl::Context* context);
 
   // TODO(hclam): Need to figure out which thread destroys this object.
   virtual ~Gles2VideoDecodeContext();
 
   //--------------------------------------------------------------------------
   // Video Decoder Thread
 
   // media::VideoDecodeContext implementation.
   virtual void* GetDevice();
   virtual void AllocateVideoFrames(int n, size_t width, size_t height,
                                    AllocationCompleteCallback* callback);
   virtual void ReleaseVideoFrames(int n, media::VideoFrame* frames);
   virtual void Destroy(DestructionCompleteCallback* callback);
 
   //--------------------------------------------------------------------------
   // Any thread
   // Accessor of the current mode of this decode context.
   bool IsMemoryMapped() const { return type_ == kMemoryMappedYuvTextures; }
 
  private:
+  // Message loop that this object lives on. This is the message loop that
+  // this object is created.
+  MessageLoop* message_loop_;
+
   // Type of storage provided by this class.
   StorageType type_;
 
-  // TODO(hclam): We should keep a ggl::Context instead.
-  WebKit::WebGLES2Context* context_;
+  // Pointer to the GLES2 context.
+  ggl::Context* context_;
 
   DISALLOW_COPY_AND_ASSIGN(Gles2VideoDecodeContext);
 };
 
 #endif  // CHROME_RENDERER_MEDIA_GLES2_VIDEO_DECODE_CONTEXT_H_