Create GoogleURLTrackerClient interface and //chrome implementation

chrome/browser/google/chrome_google_url_tracker_client.cc

+// 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.
+
+#include "chrome/browser/google/chrome_google_url_tracker_client.h"
+
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/google/google_url_tracker.h"
+#include "chrome/browser/infobars/infobar_service.h"
+#include "content/public/browser/navigation_controller.h"
+#include "content/public/browser/navigation_entry.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/web_contents.h"
+
+ChromeGoogleURLTrackerClient::
+    ChromeGoogleURLTrackerClient() : tracker_(NULL) {

[Peter Kasting, 2014/05/14 23:30:28]

Nit: Linebreak not necessary (everything will fit in 80 columns)

[blundell, 2014/05/15 07:58:03]

Done.

+}
+
+ChromeGoogleURLTrackerClient::
+    ~ChromeGoogleURLTrackerClient() {

[Peter Kasting, 2014/05/14 23:30:28]

Nit: Linebreak not necessary

[blundell, 2014/05/15 07:58:03]

Done.

+}
+
+void ChromeGoogleURLTrackerClient::SetGoogleURLTracker(
+    GoogleURLTracker* tracker) {
+  DCHECK(tracker);
+  tracker_ = tracker;
+}
+
+void ChromeGoogleURLTrackerClient::SetListeningForNavigationStart(
+    bool listen) {
+  if (listen) {
+    registrar_.Add(this, content::NOTIFICATION_NAV_ENTRY_PENDING,
+        content::NotificationService::AllBrowserContextsAndSources());
+  } else {
+    registrar_.Remove(this, content::NOTIFICATION_NAV_ENTRY_PENDING,
+        content::NotificationService::AllBrowserContextsAndSources());
+  }
+}
+
+bool ChromeGoogleURLTrackerClient::IsListeningForNavigationStart() {
+  return registrar_.IsRegistered(this, content::NOTIFICATION_NAV_ENTRY_PENDING,
+      content::NotificationService::AllBrowserContextsAndSources());
+}
+
+void ChromeGoogleURLTrackerClient::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {

[Peter Kasting, 2014/05/14 23:30:28]

Nit: Simpler:

  DCHECK_EQ(content::NOTIFICATION_NAV_ENTRY_PENDING, type);
  ... handler code

[blundell, 2014/05/15 07:58:03]

Done.

+    case content::NOTIFICATION_NAV_ENTRY_PENDING: {
+      content::NavigationController* controller =
+          content::Source<content::NavigationController>(source).ptr();
+      content::WebContents* web_contents = controller->GetWebContents();
+      InfoBarService* infobar_service =
+          InfoBarService::FromWebContents(web_contents);
+      // Because we're listening to all sources, there may be no
+      // InfoBarService for some notifications, e.g. navigations in
+      // bubbles/balloons etc.
+      if (infobar_service) {
+        tracker_->OnNavigationPending(
+            controller, infobar_service,
+            controller->GetPendingEntry()->GetUniqueID());
+      }
+      break;
+    }
+
+    default:
+      NOTREACHED() << "Unknown notification received:" << type;
+  }
+}