Add GL_EXT_color_buffer_half_float support

gpu/command_buffer/service/framebuffer_manager.cc

 // 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.
 
 #include "gpu/command_buffer/service/framebuffer_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/logging.h"
@@ skipping 251 matching lines @@
         attachment_type, max_color_attachments);
     DCHECK_NE(0u, need);
     uint32_t have = GLES2Util::GetChannelsForFormat(internal_format);
 
     // Workaround for NVIDIA drivers that incorrectly expose these formats as
     // renderable:
     if (internal_format == GL_LUMINANCE || internal_format == GL_ALPHA ||
         internal_format == GL_LUMINANCE_ALPHA) {
       return false;
     }
+    // Disallow RGB16F, because it is only supported in ES2 and not ES3.
+    if (internal_format == GL_RGB16F) {
+      return false;
+    }
     return (need & have) != 0;
   }
 
   size_t GetSignatureSize(TextureManager* texture_manager) const override {
     return texture_manager->GetSignatureSize();
   }
 
   void AddToSignature(TextureManager* texture_manager,
                       std::string* signature) const override {
     DCHECK(signature);
@@ skipping 786 matching lines @@
 
 bool FramebufferManager::IsComplete(
     Framebuffer* framebuffer) {
   DCHECK(framebuffer);
   return framebuffer->framebuffer_complete_state_count_id() ==
       framebuffer_state_change_count_;
 }
 
 }  // namespace gles2
 }  // namespace gpu