Add support for distilling current WebContents

components/dom_distiller/content/web_contents_main_frame_observer.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 COMPONENTS_DOM_DISTILLER_CONTENT_WEB_CONTENTS_MAIN_FRAME_OBSERVER_H_
+#define COMPONENTS_DOM_DISTILLER_CONTENT_WEB_CONTENTS_MAIN_FRAME_OBSERVER_H_
+
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
+
+namespace dom_distiller {
+
+// Tracks whether DocumentLoadedInFrame has been called for the main frame for
+// the current main frame for the given WebContents. It removes itself as an
+// observer if the WebContents is destroyed or the render process is gone.
+class WebContentsMainFrameObserver
+    : public content::WebContentsObserver,
+      public content::WebContentsUserData<WebContentsMainFrameObserver> {
+ public:
+  virtual ~WebContentsMainFrameObserver();
+
+  bool is_document_loaded_in_main_frame() {
+    return is_document_loaded_in_main_frame_;
+  }
+
+  bool is_initialized() { return is_initialized_; }
+
+  // content::WebContentsObserver implementation.
+  virtual void DocumentLoadedInFrame(
+      int64 frame_id,
+      content::RenderViewHost* render_view_host) OVERRIDE;
+  virtual void DidNavigateMainFrame(
+      const content::LoadCommittedDetails& details,
+      const content::FrameNavigateParams& params) OVERRIDE;
+  virtual void RenderProcessGone(base::TerminationStatus status) OVERRIDE;
+  virtual void WebContentsDestroyed() OVERRIDE;
+
+ private:
+  explicit WebContentsMainFrameObserver(content::WebContents* web_contents);
+  friend class content::WebContentsUserData<WebContentsMainFrameObserver>;
+
+  // Removes the observer and clears the WebContents member.
+  void CleanUp();
+
+  // Whether DocumentLoadedInFrame has been called for the tracked WebContents
+  // for the current main frame. This is cleared when the main frame navigates,
+  // and set again when DocumentLoadedInFrame is called for the main frame.
+  bool is_document_loaded_in_main_frame_;
+
+  // Whether this object has been correctly initialized. This is set as soon as
+  // at least one call to DidNavigateMainFrame has happened.
+  bool is_initialized_;
+
+  // The WebContents this class is tracking.
+  content::WebContents* web_contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebContentsMainFrameObserver);
+};
+
+}  // namespace dom_distiller
+
+#endif  // COMPONENTS_DOM_DISTILLER_CONTENT_WEB_CONTENTS_MAIN_FRAME_OBSERVER_H_