Fix crash when clicking the close button on a closing infobar.

chrome/browser/tab_contents/infobar.cc

Index: chrome/browser/tab_contents/infobar.cc
===================================================================
--- chrome/browser/tab_contents/infobar.cc	(revision 91189)
+++ chrome/browser/tab_contents/infobar.cc	(working copy)
@@ -101,7 +101,12 @@
 }
 
 void InfoBar::RemoveInfoBar() {
-  if (!delegate_)
+  // If the user clicks the close button when the infobar is already closing
+  // (e.g. because this is the second click of a double-click on the button),
+  // |owner_| can be NULL here, in which case we don't want to call
+  // InfoBarDismissed() either (since this can lead to us double-recording
+  // dismissals).
+  if (!delegate_ || !owner_)
     return;
   delegate_->InfoBarDismissed();
   owner_->RemoveInfoBar(delegate_);