Revert of Showing previews UI for Offline Previews

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

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageBridge.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageBridge.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageBridge.java
index aca92e50424c888b2e88723f1b267aeb4cc54c95..b3912fc66c46162eb4bb6691f54fea3376809637 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageBridge.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageBridge.java
@@ -403,14 +403,6 @@
         return nativeGetOfflinePageHeaderForReload(mNativeOfflinePageBridge, webContents);
     }
 
-    /**
-     * @return True if an offline preview is being shown.
-     * @param webContents Contents of the page to check.
-     */
-    public boolean isShowingOfflinePreview(WebContents webContents) {
-        return nativeIsShowingOfflinePreview(mNativeOfflinePageBridge, webContents);
-    }
-
     private static class CheckPagesExistOfflineCallbackInternal {
         private Callback<Set<String>> mCallback;
 
@@ -537,6 +529,4 @@
             String clientNamespace, String clientId, boolean userRequested);
     private native String nativeGetOfflinePageHeaderForReload(
             long nativeOfflinePageBridge, WebContents webContents);
-    private native boolean nativeIsShowingOfflinePreview(
-            long nativeOfflinePageBridge, WebContents webContents);
 }