Add command buffer support for EXT_sRGB_write_control

gpu/command_buffer/service/context_state.h

 // Copyright (c) 2012 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.
 
 // This file contains the ContextState class.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_CONTEXT_STATE_H_
 #define GPU_COMMAND_BUFFER_SERVICE_CONTEXT_STATE_H_
 
 #include <memory>
@@ skipping 336 matching lines @@
 
   // If a buffer object is bound to PIXEL_PACK_BUFFER, set all pack parameters
   // user values; otherwise, set them to 0.
   void UpdatePackParameters() const;
   // If a buffer object is bound to PIXEL_UNPACK_BUFFER, set all unpack
   // parameters user values; otherwise, set them to 0.
   void UpdateUnpackParameters() const;
 
   void InitStateManual(const ContextState* prev_state) const;
 
-  bool framebuffer_srgb_;
+  // EnableDisableFramebufferSRGB is called at very high frequency. Cache the
+  // true value of FRAMEBUFFER_SRGB, if we know it, to elide some of these
+  // calls.
+  bool framebuffer_srgb_valid_ = false;
+  bool framebuffer_srgb_ = false;
 
   // Generic vertex attrib base types: FLOAT, INT, or UINT.
   // Each base type is encoded into 2 bits, the lowest 2 bits for location 0,
   // the highest 2 bits for location (max_vertex_attribs - 1).
   std::vector<uint32_t> generic_attrib_base_type_mask_;
 
   GLfloat line_width_min_ = 0.0f;
   GLfloat line_width_max_ = 1.0f;
 
   FeatureInfo* feature_info_;
   std::unique_ptr<ErrorState> error_state_;
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_CONTEXT_STATE_H_