Fix crasher caused by non-ExtensionHost-based RenderViewHostDelegates in extension processes (notifications or sidebars currently) when viewing about:memory.
Fix crasher caused by non-ExtensionHost-based RenderViewHostDelegates in
extension processes (notifications or sidebars currently) when viewing
about:memory.

BUG=68773
TEST=create an HTML notification (webkitNotifications.createHTMLNotification)
from an extension process and show about:memory.  the browser shouldn't crash.

Review URL: http://codereview.chromium.org/6174003

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@70852 0039d316-1c4b-4281-b951-d872f2087c98

adobe/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,gavinp/chromium,ropik/chromium,gavinp/chromium,ropik/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,ropik/chromium,gavinp/chromium,Crystalnix/house-of-life-chromium,Crystalnix/house-of-life-chromium,gavinp/chromium,ropik/chromium,ropik/chromium,adobe/chromium,adobe/chromium,Crystalnix/house-of-life-chromium,adobe/chromium,Crystalnix/house-of-life-chromium,Crystalnix/house-of-life-chromium,gavinp/chromium,ropik/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,Crystalnix/house-of-life-chromium,adobe/chromium,yitian134/chromium,Crystalnix/house-of-life-chromium,gavinp/chromium,yitian134/chromium,Crystalnix/house-of-life-chromium,adobe/chromium,ropik/chromium,Crystalnix/house-of-life-chromium,yitian134/chromium,yitian134/chromium,ropik/chromium,yitian134/chromium,Crystalnix/house-of-life-chromium,yitian134/chromium,Crystalnix/house-of-life-chromium,adobe/chromium,gavinp/chromium