Showing previews UI for Offline Previews

chrome/browser/android/offline_pages/offline_page_utils.h

Index: chrome/browser/android/offline_pages/offline_page_utils.h
diff --git a/chrome/browser/android/offline_pages/offline_page_utils.h b/chrome/browser/android/offline_pages/offline_page_utils.h
index 80488713afd8e75ef1b5dad32c4fd79aabb447c0..2e770c9b39bf99502fbe2fe97a267e0e4baad417 100644
--- a/chrome/browser/android/offline_pages/offline_page_utils.h
+++ b/chrome/browser/android/offline_pages/offline_page_utils.h
@@ -37,20 +37,24 @@ class OfflinePageUtils {
   // returned pointer is owned by the web_contents and may be deleted by user
   // navigation, so it is unsafe to store a copy of the returned pointer.
   static const OfflinePageItem* GetOfflinePageFromWebContents(
       content::WebContents* web_contents);
 
   // Gets the offline header provided when loading the offline page for the
   // given web contents.
   static const OfflinePageHeader* GetOfflineHeaderFromWebContents(
       content::WebContents* web_contents);
 
+  // Returns whether the offline page corresponding to |web_contents| is part of

[jianli, 2016/10/25 22:14:16]

The comment is a bit hard to understand. How about:
  // Returns true if the offline page is shown for previewing purpose.

[RyanSturm, 2016/10/25 23:08:26]

Done.

+  // previews/. If there is no offline page for |web_contents|, returns false.
+  static bool IsShowingOfflinePreview(content::WebContents* web_contents);
+
   // Gets an Android Tab ID from a tab containing |web_contents|. Returns false,
   // when tab is not available. Returns true otherwise and sets |tab_id| to the
   // ID of the tab.
   static bool GetTabId(content::WebContents* web_contents, int* tab_id);
 
   static void CheckExistenceOfPagesWithURL(
       content::BrowserContext* browser_context,
       const std::string name_space,
       const GURL& offline_url,
       const base::Callback<void(bool)>& callback);