Showing previews UI for Offline Previews

chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
index 68a4bb306b176bc1746ca4c3aca01a4c5056f6a5..7fbda68bc029710fa6391777e694f9d97a461d8e 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
@@ -2908,20 +2908,27 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
     }
 
     /**
      * @return True if the offline page is opened.
      */
     public boolean isOfflinePage() {
         return isFrozen() ? false : nativeIsOfflinePage(mNativeTabAndroid);
     }
 
     /**
+     * @return True if the offline page is opened.
+     */
+    public boolean isShowingOfflinePreview() {
+        return isFrozen() ? false : nativeIsShowingOfflinePreview(mNativeTabAndroid);
+    }
+
+    /**
      * @return The offline page if tab currently displays it, null otherwise.
      */
     public OfflinePageItem getOfflinePage() {
         return isFrozen() ? null : nativeGetOfflinePage(mNativeTabAndroid);
     }
 
     /**
      * Shows the list of offline pages. This should only be hit when offline pages feature is
      * enabled.
      */
@@ -3279,20 +3286,21 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
     private native void nativeSetActiveNavigationEntryTitleForUrl(long nativeTabAndroid, String url,
             String title);
     private native boolean nativePrint(long nativeTabAndroid);
     private native Bitmap nativeGetFavicon(long nativeTabAndroid);
     private native void nativeCreateHistoricalTab(long nativeTabAndroid);
     private native void nativeUpdateTopControlsState(
             long nativeTabAndroid, int constraints, int current, boolean animate);
     private native void nativeLoadOriginalImage(long nativeTabAndroid);
     private native long nativeGetBookmarkId(long nativeTabAndroid, boolean onlyEditable);
     private native boolean nativeIsOfflinePage(long nativeTabAndroid);
+    private native boolean nativeIsShowingOfflinePreview(long nativeTabAndroid);
     private native OfflinePageItem nativeGetOfflinePage(long nativeTabAndroid);
     private native void nativeSetInterceptNavigationDelegate(long nativeTabAndroid,
             InterceptNavigationDelegate delegate);
     private native void nativeAttachToTabContentManager(long nativeTabAndroid,
             TabContentManager tabContentManager);
     private native void nativeAttachOverlayWebContents(
             long nativeTabAndroid, WebContents webContents, boolean visible);
     private native void nativeDetachOverlayWebContents(
             long nativeTabAndroid, WebContents webContents);
     private native boolean nativeHasPrerenderedUrl(long nativeTabAndroid, String url);