Android screen orientation lock should lock/unlock the same activity

content/shell/android/java/src/org/chromium/content_shell/Shell.java

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.content_shell;
 
 import android.app.Activity;
 import android.content.Context;
 import android.graphics.drawable.ClipDrawable;
 import android.text.TextUtils;
@@ skipping 338 matching lines @@
             }
         };
     }
 
     @CalledByNative
     public ContentVideoViewEmbedder getContentVideoViewEmbedder() {
         return new ActivityContentVideoViewEmbedder((Activity) getContext()) {
             @Override
             public void enterFullscreenVideo(View view, boolean isVideoLoaded) {
                 super.enterFullscreenVideo(view, isVideoLoaded);
-                mContentViewRenderView.setOverlayVideoMode(true);
+                if (mContentViewRenderView != null) {
+                    mContentViewRenderView.setOverlayVideoMode(true);
+                }
             }
 
             @Override
             public void exitFullscreenVideo() {
                 super.exitFullscreenVideo();
-                mContentViewRenderView.setOverlayVideoMode(false);
+                if (mContentViewRenderView != null) {
+                    mContentViewRenderView.setOverlayVideoMode(false);
+                }
             }
         };
     }
 
     /**
      * Enable/Disable navigation(Prev/Next) button if navigation is allowed/disallowed
      * in respective direction.
      * @param controlId Id of button to update
      * @param enabled enable/disable value
      */
@@ skipping 32 matching lines @@
                 Context.INPUT_METHOD_SERVICE);
         if (visible) {
             imm.showSoftInput(mUrlTextView, InputMethodManager.SHOW_IMPLICIT);
         } else {
             imm.hideSoftInputFromWindow(mUrlTextView.getWindowToken(), 0);
         }
     }
 
     private static native void nativeCloseShell(long shellPtr);
 }