DCHECK if shader compilation fails that it's due to context loss.

cc/test/test_gles2_interface.h

 // Copyright 2013 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 CC_TEST_TEST_GLES2_INTERFACE_H_
 #define CC_TEST_TEST_GLES2_INTERFACE_H_
 
 #include "gpu/command_buffer/client/gles2_interface_stub.h"
 
 namespace cc {
@@ skipping 159 matching lines @@
   void ProduceTextureCHROMIUM(GLenum target, const GLbyte* mailbox) override;
   void ProduceTextureDirectCHROMIUM(GLuint texture,
                                     GLenum target,
                                     const GLbyte* mailbox) override;
   void ConsumeTextureCHROMIUM(GLenum target, const GLbyte* mailbox) override;
   GLuint CreateAndConsumeTextureCHROMIUM(GLenum target,
                                          const GLbyte* mailbox) override;
 
   void ResizeCHROMIUM(GLuint width, GLuint height, float device_scale) override;
   void LoseContextCHROMIUM(GLenum current, GLenum other) override;
+  GLboolean IsContextLost() override;
 
  private:
   TestWebGraphicsContext3D* test_context_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_TEST_GLES2_INTERFACE_H_