Create GoogleURLTrackerClient interface and //chrome implementation

components/google/core/browser/google_url_tracker_client.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_GOOGLE_GOOGLE_URL_TRACKER_CLIENT_H_
+#define COMPONENTS_GOOGLE_GOOGLE_URL_TRACKER_CLIENT_H_
+
+#include "base/macros.h"
+
+class GoogleURLTracker;
+
+// Interface by which GoogleURLTracker communicates with its embedder.
+class GoogleURLTrackerClient {
+ public:
+  GoogleURLTrackerClient();
+  virtual ~GoogleURLTrackerClient();
+
+  // Sets the GoogleURLTracker that is associated with this client.
+  void set_google_url_tracker(GoogleURLTracker* google_url_tracker) {
+    google_url_tracker_ = google_url_tracker;
+  }
+
+  // Enables or disables listening for navigation starts. OnNavigationPending
+  // will be called for each navigation start if listening is enabled.
+  virtual void SetListeningForNavigationStart(bool listen) = 0;
+
+  // Returns whether or not the client is currently listening for navigation
+  // starts.
+  virtual bool IsListeningForNavigationStart() = 0;
+
+ protected:
+  GoogleURLTracker* google_url_tracker() { return google_url_tracker_; }
+
+ private:
+  GoogleURLTracker* google_url_tracker_;
+
+  DISALLOW_COPY_AND_ASSIGN(GoogleURLTrackerClient);
+};
+
+#endif  // COMPONENTS_GOOGLE_GOOGLE_URL_TRACKER_CLIENT_H_