Speculative hardening of fullscreen infobar code.

chrome/browser/android/fullscreen/fullscreen_infobar_delegate.cc

 // Copyright 2015 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.
 
 #include "chrome/browser/android/fullscreen/fullscreen_infobar_delegate.h"
 
 #include "base/android/jni_string.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/android/tab_android.h"
@@ skipping 34 matching lines @@
 }
 
 FullscreenInfoBarDelegate::~FullscreenInfoBarDelegate() {
   if (!j_delegate_.is_null()) {
     Java_FullscreenInfoBarDelegate_onInfoBarDismissed(
         base::android::AttachCurrentThread(), j_delegate_.obj());
   }
 }
 
 void FullscreenInfoBarDelegate::CloseFullscreenInfoBar(
-    JNIEnv* env, jobject obj, jobject tab) {
+    JNIEnv* env, jobject obj) {
   j_delegate_.Reset();
-  TabAndroid* tab_android = TabAndroid::GetNativeTab(env, tab);
-  InfoBarService::FromWebContents(tab_android->web_contents())->RemoveInfoBar(
-      infobar());
+  if (infobar() && infobar()->owner())
+    infobar()->owner()->RemoveInfoBar(infobar());
 }
 
 int FullscreenInfoBarDelegate::GetIconID() const {
   return IDR_INFOBAR_FULLSCREEN;
 }
 
 base::string16 FullscreenInfoBarDelegate::GetMessageText() const {
   Profile* profile =
       ProfileManager::GetActiveUserProfile()->GetOriginalProfile();
   std::string language =
@@ skipping 17 matching lines @@
   Java_FullscreenInfoBarDelegate_onFullscreenAllowed(
       env, j_delegate_.obj(), j_origin.obj());
   return true;
 }
 
 bool FullscreenInfoBarDelegate::Cancel() {
   Java_FullscreenInfoBarDelegate_onFullscreenCancelled(
       base::android::AttachCurrentThread(), j_delegate_.obj());
   return true;
 }