chrome: Cleanup class/struct forward declarations

chrome/browser/android/compositor/scene_layer/toolbar_scene_layer.h

 // Copyright 2016 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 CHROME_BROWSER_ANDROID_COMPOSITOR_SCENE_LAYER_TOOLBAR_SCENE_LAYER_H_
 #define CHROME_BROWSER_ANDROID_COMPOSITOR_SCENE_LAYER_TOOLBAR_SCENE_LAYER_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_weak_ref.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
 #include "chrome/browser/android/compositor/scene_layer/scene_layer.h"
 #include "ui/android/resources/resource_manager_impl.h"
 
 namespace cc {
 class Layer;
-class SolidColorLayer;
 }
 
 namespace android {
 
 class ToolbarLayer;
 
 class ToolbarSceneLayer : public SceneLayer {
  public:
   ToolbarSceneLayer(JNIEnv* env, jobject jobj);
   ~ToolbarSceneLayer() override;
@@ skipping 44 matching lines @@
   scoped_refptr<ToolbarLayer> toolbar_layer_;
 
   DISALLOW_COPY_AND_ASSIGN(ToolbarSceneLayer);
 };
 
 bool RegisterToolbarSceneLayer(JNIEnv* env);
 
 }  // namespace android
 
 #endif  // CHROME_BROWSER_ANDROID_COMPOSITOR_SCENE_LAYER_TOOLBAR_SCENE_LAYER_H_