Introduce background.scripts feature for extension manifests.

This optimizes for the common use case where background pages
just include a reference to one or more script files and no
additional HTML.

BUG=107791


Review URL: http://codereview.chromium.org/9150008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@117110 0039d316-1c4b-4281-b951-d872f2087c98
void TestingAutomationProvider::HandleOpenFindInPageRequest(
    const IPC::Message& message, int handle) {
  if (browser_tracker_->ContainsHandle(handle)) {
    Browser* browser = browser_tracker_->GetResource(handle);
    browser->FindInPage(false, false);
  }
}

void TestingAutomationProvider::HandleOpenFindInPageRequest(
    const IPC::Message& message, int handle) {
  if (browser_tracker_->ContainsHandle(handle)) {
    Browser* browser = browser_tracker_->GetResource(handle);
    browser->FindInPage(false, false);
  }
}
