DevTools: Add workerShadowPageLoaded method to shared/service worker clients...

DevTools: Add workerShadowPageLoaded method to shared/service worker clients for further plumbing into the browser.

This method is going to be used as a new signal for opening worker frontend when 'debug on start' option is enabled.

BUG=404355

Review URL: https://codereview.chromium.org/483813002

git-svn-id: svn://svn.chromium.org/blink/trunk@180480 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/public/web/WebServiceWorkerContextClient.h

@@ -71,6 +71,9 @@ public:
     // WebEmbeddedWorker.resumeAfterDownload() is invoked.
     virtual void didPauseAfterDownload() { }
 
+    // ServiceWorker has prepared everything for script loading and is now ready for inspection.
+    virtual void workerReadyForInspection() { }
+
     // A new WorkerGlobalScope is created and started to run on the
     // worker thread.
     // This also gives back a proxy to the client to talk to the

third_party/WebKit/public/web/WebSharedWorkerClient.h

@@ -50,6 +50,7 @@ class WebSharedWorkerClient {
 public:
     virtual void workerContextClosed() = 0;
     virtual void workerContextDestroyed() = 0;
+    virtual void workerReadyForInspection() { }
     virtual void workerScriptLoaded() = 0;
     virtual void workerScriptLoadFailed() = 0;
     virtual void selectAppCacheID(long long) = 0;