Showing previews UI for Offline Previews

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
index f60a6d45df3fa42c959a7d30e57ec4231b27824e..0d52d7024ac164b94ab0e584f469068b1af24f94 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
@@ -538,20 +538,29 @@ public class OfflinePageUtils {
      * Retrieves the extra request header to reload the offline page.
      * @param tab The current tab.
      * @return The extra request header string.
      */
     public static String getOfflinePageHeaderForReload(Tab tab) {
         OfflinePageBridge offlinePageBridge = getInstance().getOfflinePageBridge(tab.getProfile());
         if (offlinePageBridge == null) return "";
         return offlinePageBridge.getOfflinePageHeaderForReload(tab.getWebContents());
     }
 
+    /**
+     * @return True if an offline preview is being shown.

[jianli, 2016/10/25 23:55:27]

nit: add comment for tab parameter

[RyanSturm, 2016/10/27 00:01:01]

Done.

+     */
+    public static boolean isShowingOfflinePreview(Tab tab) {
+        OfflinePageBridge offlinePageBridge = getInstance().getOfflinePageBridge(tab.getProfile());
+        if (offlinePageBridge == null) return false;
+        return offlinePageBridge.isShowingOfflinePreview(tab.getWebContents());
+    }
+
     private static boolean isPowerConnected(Intent batteryStatus) {
         int status = batteryStatus.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
         boolean isConnected = (status == BatteryManager.BATTERY_STATUS_CHARGING
                 || status == BatteryManager.BATTERY_STATUS_FULL);
         Log.d(TAG, "Power connected is " + isConnected);
         return isConnected;
     }
 
     private static int batteryPercentage(Intent batteryStatus) {
         int level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);