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

cc/test/test_gles2_interface.cc

 // 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.
 
 #include "cc/test/test_gles2_interface.h"
 
 #include "base/logging.h"
 #include "cc/test/test_web_graphics_context_3d.h"
 
 namespace cc {
@@ skipping 405 matching lines @@
 void TestGLES2Interface::ResizeCHROMIUM(GLuint width,
                                         GLuint height,
                                         float device_scale) {
   test_context_->reshapeWithScaleFactor(width, height, device_scale);
 }
 
 void TestGLES2Interface::LoseContextCHROMIUM(GLenum current, GLenum other) {
   test_context_->loseContextCHROMIUM(current, other);
 }
 
+GLboolean TestGLES2Interface::IsContextLost() {
+  return test_context_->isContextLost();
+}
+
 }  // namespace cc