Hook ANGLE_request_extension up to the passthrough cmd decoder.

third_party/WebKit/Source/platform/graphics/gpu/Extensions3DUtil.cpp

 // Copyright 2014 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 "platform/graphics/gpu/Extensions3DUtil.h"
 
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "wtf/PtrUtil.h"
 #include "wtf/text/CString.h"
 #include "wtf/text/StringHash.h"
@@ skipping 56 matching lines @@
     m_requestableExtensions.clear();
     initializeExtensions();
   }
   return m_enabledExtensions.contains(name);
 }
 
 bool Extensions3DUtil::isExtensionEnabled(const String& name) {
   return m_enabledExtensions.contains(name);
 }
 
+bool Extensions3DUtil::isExtensionRequestable(const String& name) {
+  return m_requestableExtensions.contains(name);
+}
+
 bool Extensions3DUtil::canUseCopyTextureCHROMIUM(GLenum destTarget,
                                                  GLenum destFormat,
                                                  GLenum destType,
                                                  GLint level) {
   // TODO(zmo): restriction of (RGB || RGBA)/UNSIGNED_BYTE/(Level 0) should be
   // lifted when GLES2Interface::CopyTextureCHROMIUM(...) are fully functional.
   if (destTarget == GL_TEXTURE_2D &&
       (destFormat == GL_RGB || destFormat == GL_RGBA) &&
       destType == GL_UNSIGNED_BYTE && !level)
     return true;
   return false;
 }
 
 }  // namespace blink