Framework to ascribe all network data use to a source.

chrome/browser/data_use_measurement/data_use_web_contents_observer.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_DATA_USE_MEASUREMENT_DATA_USE_WEB_CONTENTS_OBSERVER_H_
+#define CHROME_BROWSER_DATA_USE_MEASUREMENT_DATA_USE_WEB_CONTENTS_OBSERVER_H_
+
+#include "base/macros.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
+
+namespace content {
+class NavigationHandle;
+class RenderFrameHost;
+}
+
+namespace data_use_measurement {
+
+class ChromeDataUseAscriberService;
+
+// Propagates navigation and frame events to ChromeDataUseAscriberService.
+// We use this class instead of having ChromeDataUseAscriberService derive from
+// WebContentsObserver because each instance of WebContents needs its own
+// instance of WebContentsObserver, and ChromeDataUseAscriberService needs to
+// observe all WebContents.
+class DataUseWebContentsObserver
+    : public content::WebContentsObserver,
+      public content::WebContentsUserData<DataUseWebContentsObserver> {
+ public:
+  // Creates a DataUseWebContentsObserver for the given WebContents and
+  // ChromeDataUseAscriberService.
+  static void CreateForWebContents(content::WebContents* web_contents,
+                                   ChromeDataUseAscriberService* service);
+
+  ~DataUseWebContentsObserver() override;
+
+  // WebContentsObserver:
+  // Called when a render frame host is created.
+  void RenderFrameCreated(content::RenderFrameHost* render_frame_host) override;
+
+  // Called when a render frame host is deleted.
+  void RenderFrameDeleted(content::RenderFrameHost* render_frame_host) override;
+
+  // Called when a navigation is started.
+  void DidStartNavigation(
+      content::NavigationHandle* navigation_handle) override;
+
+  // Called when a navigation is completed.
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
+
+  // Called when a navigation is redirected.
+  void DidRedirectNavigation(
+      content::NavigationHandle* navigation_handle) override;
+
+ private:
+  friend class content::WebContentsUserData<DataUseWebContentsObserver>;
+
+  DataUseWebContentsObserver(content::WebContents* web_contents,
+                             ChromeDataUseAscriberService* service);
+  ChromeDataUseAscriberService* const service_;
+
+  DISALLOW_COPY_AND_ASSIGN(DataUseWebContentsObserver);
+};
+
+}  // namespace data_use_measurement
+
+#endif  // CHROME_BROWSER_DATA_USE_MEASUREMENT_DATA_USE_WEB_CONTENTS_OBSERVER_H_