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::IsWindowActive(int handle,
                                               bool* success,
                                               bool* is_active) {
  if (window_tracker_->ContainsHandle(handle)) {
    *is_active =
        platform_util::IsWindowActive(window_tracker_->GetResource(handle));
    *success = true;
  } else {
    *success = false;
    *is_active = false;
  }
}

void TestingAutomationProvider::IsWindowActive(int handle,
                                               bool* success,
                                               bool* is_active) {
  if (window_tracker_->ContainsHandle(handle)) {
    *is_active =
        platform_util::IsWindowActive(window_tracker_->GetResource(handle));
    *success = true;
  } else {
    *success = false;
    *is_active = false;
  }
}
