gpu: check GL_RGB565 work in ES3 context

gpu/command_buffer/service/feature_info.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.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_FEATURE_INFO_H_
 #define GPU_COMMAND_BUFFER_SERVICE_FEATURE_INFO_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 126 matching lines @@
     return disallowed_features_;
   }
 
   const gl::GLVersionInfo& gl_version_info() const {
     DCHECK(gl_version_info_.get());
     return *(gl_version_info_.get());
   }
 
   bool IsES3Capable() const;
   void EnableES3Validators();
+  void EnableES3ValidatorsForTesting();
 
   bool IsES3Enabled() const {
     return unsafe_es3_apis_enabled_;
   }
 
   bool disable_shader_translator() const { return disable_shader_translator_; }
 
   bool IsWebGLContext() const;
   bool IsWebGL1OrES2Context() const;
   bool IsWebGL2OrES3Context() const;
@@ skipping 26 matching lines @@
   // Flags for some features
   FeatureFlags feature_flags_;
 
   // Flags for Workarounds.
   const GpuDriverBugWorkarounds workarounds_;
 
   // Whether the command line switch kEnableUnsafeES3APIs is passed in.
   bool enable_unsafe_es3_apis_switch_;
 
   bool unsafe_es3_apis_enabled_;
+  bool testing_es3_apis_enabled_ = false;
 
   bool ext_color_buffer_float_available_;
   bool oes_texture_float_linear_available_;
   bool oes_texture_half_float_linear_available_;
 
   bool disable_shader_translator_;
   std::unique_ptr<gl::GLVersionInfo> gl_version_info_;
 
   DISALLOW_COPY_AND_ASSIGN(FeatureInfo);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_FEATURE_INFO_H_