Add UMA histograms for Google cached copy experiment on network error interstitial

chrome/renderer/net/net_error_page_controller.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/renderer/net/net_error_page_controller.h"
 
 #include "base/strings/string_piece.h"
 #include "chrome/renderer/net/net_error_helper.h"
 #include "content/public/renderer/render_frame.h"
 #include "gin/handle.h"
@@ skipping 34 matching lines @@
 }
 
 bool NetErrorPageController::DetailsButtonClick() {
   return ButtonClick(error_page::NetErrorHelperCore::MORE_BUTTON);
 }
 
 bool NetErrorPageController::TrackEasterEgg() {
   return ButtonClick(error_page::NetErrorHelperCore::EASTER_EGG);
 }
 
+bool NetErrorPageController::TrackCachedCopyButtonClick(bool is_default_label) {
+  return is_default_label ?
+      ButtonClick(error_page::NetErrorHelperCore::SHOW_CACHED_PAGE_BUTTON) :
+      ButtonClick(error_page::NetErrorHelperCore::SHOW_CACHED_COPY_BUTTON);
+}
+
 bool NetErrorPageController::TrackClick(const gin::Arguments& args) {
   if (!render_frame())
     return false;
 
   if (!args.PeekNext()->IsInt32())
     return false;
 
   NetErrorHelper* net_error_helper =
       content::RenderFrameObserverTracker<NetErrorHelper>::Get(render_frame());
   DCHECK(net_error_helper);
@@ skipping 26 matching lines @@
              isolate)
       .SetMethod("showSavedCopyButtonClick",
                  &NetErrorPageController::ShowSavedCopyButtonClick)
       .SetMethod("reloadButtonClick",
                  &NetErrorPageController::ReloadButtonClick)
       .SetMethod("detailsButtonClick",
                  &NetErrorPageController::DetailsButtonClick)
       .SetMethod("trackClick",
                  &NetErrorPageController::TrackClick)
       .SetMethod("trackEasterEgg",
-                 &NetErrorPageController::TrackEasterEgg);
+                 &NetErrorPageController::TrackEasterEgg)
+      .SetMethod("trackCachedCopyButtonClick",
+                 &NetErrorPageController::TrackCachedCopyButtonClick);
 }
 
 void NetErrorPageController::OnDestruct() {}