Presentation API: fix crash when unable to create a Fragment for the dialog.

chrome/android/java/src/org/chromium/chrome/browser/media/router/MediaRouteControllerDialogManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/media/router/MediaRouteControllerDialogManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/router/MediaRouteControllerDialogManager.java b/chrome/android/java/src/org/chromium/chrome/browser/media/router/MediaRouteControllerDialogManager.java
index 6697e7606912fd6ff43f45d2c164538256557312..5a9b510bd1f709cc9752c902379c8318b332dda5 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/media/router/MediaRouteControllerDialogManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/router/MediaRouteControllerDialogManager.java
@@ -8,7 +8,6 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.support.v4.app.DialogFragment;
 import android.support.v4.app.FragmentManager;
-import android.support.v7.app.MediaRouteControllerDialogFragment;
 import android.support.v7.media.MediaRouteSelector;
 import android.support.v7.media.MediaRouter;
 
@@ -38,34 +37,37 @@ public class MediaRouteControllerDialogManager extends BaseMediaRouteDialogManag
         mMediaRouteId = mediaRouteId;
     }
 
-    @Override
-    protected DialogFragment openDialogInternal(FragmentManager fm) {
-        if (fm.findFragmentByTag(DIALOG_FRAGMENT_TAG) != null) return null;
+    /**
+     * Fragment implementation for MediaRouteControllerDialogManager.
+     */
+    public static class Fragment extends BaseMediaRouteDialogManager.Fragment {
+        MediaRouter.Callback mCallback = null;
 
-        MediaRouteControllerDialogFragment fragment = new MediaRouteControllerDialogFragment() {
-            final SystemVisibilitySaver mVisibilitySaver = new SystemVisibilitySaver();
+        public Fragment() {
+            super();
+        }
 
-            @Override
-            public void onStart() {
-                mVisibilitySaver.saveSystemVisibility(getActivity());
-                super.onStart();
-            }
+        public Fragment(BaseMediaRouteDialogManager manager, MediaRouter.Callback callback) {
+            super(manager);
+            mCallback = callback;
+        }
 
-            @Override
-            public void onStop() {
-                super.onStop();
-                mVisibilitySaver.restoreSystemVisibility(getActivity());
+        @Override
+        public void onDismiss(DialogInterface dialog) {
+            if (mManager != null) {
+                mManager.delegate().onDialogCancelled();
+                mManager.androidMediaRouter().removeCallback(mCallback);
             }
 
-            @Override
-            public void onDismiss(DialogInterface dialog) {
-                delegate().onDialogCancelled();
-                androidMediaRouter().removeCallback(mCallback);
-                mDialogFragment = null;
-                super.onDismiss(dialog);
-            }
-        };
+            super.onDismiss(dialog);
+        }
+    };
+
+    @Override
+    protected DialogFragment openDialogInternal(FragmentManager fm) {
+        if (fm.findFragmentByTag(DIALOG_FRAGMENT_TAG) != null) return null;
 
+        Fragment fragment = new Fragment(this, mCallback);
         MediaRouteSelector selector = mediaSource().buildRouteSelector();
         if (selector == null) return null;