[Offline Pages] Adds Rappor metrics measuring what domains are saved & viewed.

chrome/browser/android/offline_pages/offline_page_tab_helper.cc

 // 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.
 
 #include "chrome/browser/android/offline_pages/offline_page_tab_helper.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/android/offline_pages/offline_page_utils.h"
+#include "chrome/browser/browser_process.h"
+#include "components/rappor/rappor_utils.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "net/base/net_errors.h"
 #include "net/base/network_change_notifier.h"
 #include "ui/base/page_transition_types.h"
 
@@ skipping 78 matching lines @@
       error_code != net::ERR_PROXY_CONNECTION_FAILED) {
     return;
   }
 
   // On a forward or back transition, don't affect the order of the nav stack.
   if (navigation_handle->GetPageTransition() ==
       ui::PAGE_TRANSITION_FORWARD_BACK) {
     return;
   }
 
+  GURL online_url = navigation_handle->GetURL();
+
   // When the navigation starts, we redirect immediately from online page to
   // offline version on the case that there is no network connection. If there
   // is still network connection but with no or poor network connectivity, the
   // navigation will eventually fail and we want to redirect to offline copy
   // in this case.
   GURL offline_url = offline_pages::OfflinePageUtils::GetOfflineURLForOnlineURL(
-      web_contents()->GetBrowserContext(), navigation_handle->GetURL());
+      web_contents()->GetBrowserContext(), online_url);
   if (!offline_url.is_valid())
     return;
 
+  rappor::SampleDomainAndRegistryFromGURL(
+      g_browser_process->rappor_service(),
+      "OfflinePages.OfflineVersionWasViewedWhileOffline", online_url);
+
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
       base::Bind(&OfflinePageTabHelper::Redirect,
                  weak_ptr_factory_.GetWeakPtr(),
                  navigation_handle->GetURL(), offline_url));
 }
 
 void OfflinePageTabHelper::Redirect(
     const GURL& from_url, const GURL& to_url) {
   if (to_url.SchemeIsFile()) {
     UMA_HISTOGRAM_COUNTS("OfflinePages.RedirectToOfflineCount", 1);
   } else {
     UMA_HISTOGRAM_COUNTS("OfflinePages.RedirectToOnlineCount", 1);
   }
 
   content::NavigationController::LoadURLParams load_params(to_url);
   load_params.transition_type = ui::PAGE_TRANSITION_CLIENT_REDIRECT;
   load_params.redirect_chain.push_back(from_url);
   web_contents()->GetController().LoadURLWithParams(load_params);
 }
 
 }  // namespace offline_pages