Do not require DevTools extension resources to be white-listed in manifest.

Currently, resources used by DevTools extensions need to be white-listed as web_accessible_resources in manifest. This is quite inconvenitent and appears to be an overkill, given the fact that DevTools front-end is
 (a) trusted and
 (b) picky on the frames it loads.
This change adds resources that belong to DevTools extensions and are being loaded into a DevTools front-end page to the list of exceptions from web_accessible_resources check.

BUG=none
TEST=DevToolsExtensionTest.*

Review URL: https://chromiumcodereview.appspot.com/9663076

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@126378 0039d316-1c4b-4281-b951-d872f2087c98
bool ChromeContentRendererClient::IsAdblockWithWebRequestInstalled() {
  return extension_dispatcher_->IsAdblockWithWebRequestInstalled();
}

bool ChromeContentRendererClient::IsAdblockWithWebRequestInstalled() {
  return extension_dispatcher_->IsAdblockWithWebRequestInstalled();
}
