Add GL_ANGLE_pack_reverse_row_order to command buffer

gpu/command_buffer/client/gles2_implementation.h

 // Copyright (c) 2011 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 GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 
 #include <GLES2/gl2.h>
 
 #include <map>
@@ skipping 184 matching lines @@
 
   void FreeTextureId(GLuint id) {
     id_handlers_[id_namespaces::kTextures]->FreeIds(1, &id);
   }
 
   void SetSharedMemoryChunkSizeMultiple(unsigned int multiple);
 
   void FreeUnusedSharedMemory();
 
  private:
+
+  // Used to track whether an extension is available
+  enum ExtensionStatus {
+      kAvailableExtensionStatus,
+      kUnavailableExtensionStatus,
+      kUnknownExtensionStatus
+  };
+
   // Wraps RingBufferWrapper to provide aligned allocations.
   class AlignedRingBuffer : public RingBufferWrapper {
    public:
     AlignedRingBuffer(RingBuffer::Offset base_offset,
                       unsigned int size,
                       CommandBufferHelper *helper,
                       void *base)
         : RingBufferWrapper(base_offset, size, helper, base) {
     }
 
@@ skipping 116 matching lines @@
   uint32 result_shm_offset() const {
     return result_shm_offset_;
   }
 
   // Gets the value of the result.
   template <typename T>
   T GetResultAs() const {
     return static_cast<T>(result_buffer_);
   }
 
+  // Lazily determines if GL_ANGLE_pack_reverse_row_order is available
+  bool IsAnglePackReverseRowOrderAvailable();
+
   // Gets the GLError through our wrapper.
   GLenum GetGLError();
 
   // Sets our wrapper for the GLError.
   void SetGLError(GLenum error, const char* msg);
 
   // Returns the last error and clears it. Useful for debugging.
   const std::string& GetLastError() {
     return last_error_;
   }
@@ skipping 74 matching lines @@
   scoped_ptr<IdHandlerInterface> id_handlers_[id_namespaces::kNumIdNamespaces];
   AlignedRingBuffer transfer_buffer_;
   int transfer_buffer_id_;
   void* result_buffer_;
   uint32 result_shm_offset_;
   std::string last_error_;
 
   std::queue<int32> swap_buffers_tokens_;
   std::queue<int32> rate_limit_tokens_;
 
+  ExtensionStatus angle_pack_reverse_row_order_status;
+
   GLState gl_state_;
 
   // pack alignment as last set by glPixelStorei
   GLint pack_alignment_;
 
   // unpack alignment as last set by glPixelStorei
   GLint unpack_alignment_;
 
   // unpack yflip as last set by glPixelstorei
   bool unpack_flip_y_;
 
+  // pack reverse row order as last set by glPixelstorei
+  bool pack_reverse_row_order_;
+
   scoped_array<TextureUnit> texture_units_;
 
   // 0 to gl_state_.max_combined_texture_image_units.
   GLuint active_texture_unit_;
 
   GLuint bound_framebuffer_;
   GLuint bound_renderbuffer_;
 
   // The currently bound array buffer.
   GLuint bound_array_buffer_id_;
@@ skipping 74 matching lines @@
 
 inline bool GLES2Implementation::GetTexParameterivHelper(
     GLenum /* target */, GLenum /* pname */, GLint* /* params */) {
   return false;
 }
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_