Speculative hardening of fullscreen infobar code.

chrome/browser/android/fullscreen/fullscreen_infobar_delegate.cc

Index: chrome/browser/android/fullscreen/fullscreen_infobar_delegate.cc
diff --git a/chrome/browser/android/fullscreen/fullscreen_infobar_delegate.cc b/chrome/browser/android/fullscreen/fullscreen_infobar_delegate.cc
index 04d0ab359586f089979221ed4653d78790e485bf..b7d222dc41f9b61beb079c133af091e1d1b68617 100644
--- a/chrome/browser/android/fullscreen/fullscreen_infobar_delegate.cc
+++ b/chrome/browser/android/fullscreen/fullscreen_infobar_delegate.cc
@@ -52,11 +52,10 @@ FullscreenInfoBarDelegate::~FullscreenInfoBarDelegate() {
 }
 
 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 {