Some class comments for WebTestProxy and WebTestProxyBase.

content/shell/renderer/test_runner/web_test_proxy.h

 // 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.
 
 #ifndef CONTENT_SHELL_RENDERER_TEST_RUNNER_WEB_TEST_PROXY_H_
 #define CONTENT_SHELL_RENDERER_TEST_RUNNER_WEB_TEST_PROXY_H_
 
 #include <deque>
 #include <map>
 #include <string>
@@ skipping 64 matching lines @@
 namespace content {
 
 class MockWebSpeechRecognizer;
 class RenderFrame;
 class SpellCheckClient;
 class TestInterfaces;
 class WebTestDelegate;
 class WebTestInterfaces;
 class WebUserMediaClientMock;
 
+// WebTestProxyBase is the "brain" of WebTestProxy in the sense that
+// WebTestProxy does the bridge between RenderViewImpl and WebTestProxyBase and
+// when it requires a behavior to be different from the usual, it will call
+// WebTestProxyBase that implements the expected behavior.
+// See WebTestProxy class comments for more information.
 class WebTestProxyBase : public blink::WebCompositeAndReadbackAsyncCallback {
  public:
   void SetInterfaces(WebTestInterfaces* interfaces);
   void SetDelegate(WebTestDelegate* delegate);
   void set_widget(blink::WebWidget* widget) { web_widget_ = widget; }
 
   void Reset();
 
   blink::WebSpellCheckClient* GetSpellCheckClient() const;
   blink::WebColorChooser* CreateColorChooser(
@@ skipping 144 matching lines @@
 
   scoped_ptr<blink::WebMIDIClientMock> m_midiClient;
   scoped_ptr<MockWebSpeechRecognizer> m_speechRecognizer;
 
   std::string accept_languages_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WebTestProxyBase);
 };
 
-// Use this template to inject methods into your WebViewClient/WebFrameClient
-// implementation required for the running layout tests.
+// WebTestProxy is used during LayoutTests and always instantiated, at time of
+// writing with Base=RenderViewImpl. It does not directly inherit from it for
+// layering purposes.
+// The intent of that class is to wrap RenderViewImpl for tests purposes in
+// order to reduce the amount of test specific code in the production code.
+// WebTestProxy is only doing the glue between RenderViewImpl and
+// WebTestProxyBase, that means that there is no logic living in this class
+// except deciding which base class should be called (could be both).
+//
+// Examples of usage:
+//  * when a fooClient has a mock implementation, WebTestProxy can override the
+//    fooClient() call and have WebTestProxyBase return the mock implementation.
+//  * when a value needs to be overridden by LayoutTests, WebTestProxy can
+//    override RenderViewImpl's getter and call a getter from WebTestProxyBase
+//    instead. In addition, WebTestProxyBase will have a public setter that
+//    could be called from the TestRunner.
 template <class Base, typename T>
 class WebTestProxy : public Base, public WebTestProxyBase {
  public:
   explicit WebTestProxy(T t) : Base(t) {}
 
   virtual ~WebTestProxy() {}
 
   // WebViewClient implementation.
   virtual void scheduleAnimation() { WebTestProxyBase::ScheduleAnimation(); }
   virtual void postAccessibilityEvent(const blink::WebAXObject& object,
@@ skipping 87 matching lines @@
     return WebTestProxy::acceptLanguages();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WebTestProxy);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_SHELL_RENDERER_TEST_RUNNER_WEB_TEST_PROXY_H_