Bookmarks Bar is displayed when visiting about:crash after chrome://newtab.

Even if a renderer was crashed by chrome://crash (or about:crash), Browser couldn't detect it.

I added code to make Browser handle it when a tab is invalidated.  Besides, I fixed
BookmarkTabHelper::ShouldShowBookmarkBar() so that it returns false when an instance
of WebContents doesn't run.

BUG=30175
TEST=Manual

Review URL: https://chromiumcodereview.appspot.com/12330046

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@189153 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/ui/sad_tab_helper.cc b/chrome/browser/ui/sad_tab_helper.cc
index e302dd2e..9d834a6 100644
--- a/chrome/browser/ui/sad_tab_helper.cc
+++ b/chrome/browser/ui/sad_tab_helper.cc
@@ -33,9 +33,7 @@
   if (sad_tab_)
     return;
 
-  if (status == base::TERMINATION_STATUS_ABNORMAL_TERMINATION ||
-      status == base::TERMINATION_STATUS_PROCESS_WAS_KILLED ||
-      status == base::TERMINATION_STATUS_PROCESS_CRASHED)
+  if (chrome::SadTab::ShouldShow(status))
     InstallSadTab(status);
 }