Update offline pages UMAs

chrome/browser/android/offline_pages/offline_page_tab_helper.cc

Index: chrome/browser/android/offline_pages/offline_page_tab_helper.cc
diff --git a/chrome/browser/android/offline_pages/offline_page_tab_helper.cc b/chrome/browser/android/offline_pages/offline_page_tab_helper.cc
index f818cf64c8cd76c578e390e6ca70bdb5b980c2f4..5010e27904537bf1d3d7b7c372d637b7f5d2e6aa 100644
--- a/chrome/browser/android/offline_pages/offline_page_tab_helper.cc
+++ b/chrome/browser/android/offline_pages/offline_page_tab_helper.cc
@@ -89,6 +89,7 @@ void OfflinePageTabHelper::DidFinishNavigation(
   if (error_code == net::OK &&
       OfflinePageUtils::IsOfflinePage(
           web_contents()->GetBrowserContext(), navigation_handle->GetURL())) {
+    UMA_HISTOGRAM_BOOLEAN("OfflinePages.ShowOfflinePageWhenOffline", true);

[fgorski, 2016/05/17 03:53:23]

nit: this is a bit forward looking and perhaps we want to handle it differently
once NQE is available, but did you consider a case where we are not exactly
offline? E.g. Because NQE told us to. Will this name still work? Or will we
define a new UMA?

     OfflinePageUtils::MarkPageAccessed(
         web_contents()->GetBrowserContext(), navigation_handle->GetURL());
   }
@@ -104,6 +105,7 @@ void OfflinePageTabHelper::DidFinishNavigation(
   // On a forward or back transition, don't affect the order of the nav stack.
   if (navigation_handle->GetPageTransition() ==
       ui::PAGE_TRANSITION_FORWARD_BACK) {
+    UMA_HISTOGRAM_BOOLEAN("OfflinePages.ShowOfflinePageWhenOffline", false);
     return;
   }
 
@@ -114,8 +116,10 @@ void OfflinePageTabHelper::DidFinishNavigation(
   // in this case.
   GURL offline_url = offline_pages::OfflinePageUtils::GetOfflineURLForOnlineURL(
       web_contents()->GetBrowserContext(), navigation_handle->GetURL());
-  if (!offline_url.is_valid())
+  if (!offline_url.is_valid()) {
+    UMA_HISTOGRAM_BOOLEAN("OfflinePages.ShowOfflinePageWhenOffline", false);
     return;
+  }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,