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::HandleInspectElementRequest(
    int handle, int x, int y, IPC::Message* reply_message) {
  WebContents* web_contents = GetWebContentsForHandle(handle, NULL);
  if (web_contents) {
    DCHECK(!reply_message_);
    reply_message_ = reply_message;

    DevToolsWindow::InspectElement(web_contents->GetRenderViewHost(), x, y);
  } else {
    AutomationMsg_InspectElement::WriteReplyParams(reply_message, -1);
    Send(reply_message);
  }
}

void TestingAutomationProvider::HandleInspectElementRequest(
    int handle, int x, int y, IPC::Message* reply_message) {
  WebContents* web_contents = GetWebContentsForHandle(handle, NULL);
  if (web_contents) {
    DCHECK(!reply_message_);
    reply_message_ = reply_message;

    DevToolsWindow::InspectElement(web_contents->GetRenderViewHost(), x, y);
  } else {
    AutomationMsg_InspectElement::WriteReplyParams(reply_message, -1);
    Send(reply_message);
  }
}
