Add js api for hosted/pacakged apps to request notification authorization

chrome/browser/extensions/app_notify_channel_setup.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/extensions/app_notify_channel_setup.h"
+
+#include "content/browser/browser_thread.h"
+
+AppNotifyChannelSetup::AppNotifyChannelSetup(
+    int request_id,
+    const std::string& client_id,
+    const GURL& requestor_url,
+    base::WeakPtr<AppNotifyChannelSetup::Delegate> delegate)
+    : request_id_(request_id),
+      client_id_(client_id),
+      requestor_url_(requestor_url),
+      delegate_(delegate) {}
+
+AppNotifyChannelSetup::~AppNotifyChannelSetup() {}
+
+void AppNotifyChannelSetup::Start() {
+  AddRef(); // Balanced in ReportResult.
+
+
+  // TODO(asargent) - We will eventually check here whether the user is logged
+  // in to the browser or not. If they are, we'll make a request to a server
+  // with the browser login credentials to get a channel id for the app to use
+  // in server pushed notifications. If they are not logged in, we'll prompt
+  // for login and if they sign in, then continue as in the first case.
+  // Otherwise we'll return an error message.
+
+  // For now, just reply with an error of 'not_implemented'.
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      NewRunnableMethod(this,
+                        &AppNotifyChannelSetup::ReportResult,
+                        std::string(),
+                        std::string("not_implemented")));
+}
+
+void AppNotifyChannelSetup::ReportResult(
+    const std::string& channel_id,
+    const std::string& error) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (delegate_)

[Aaron Boodman, 2011/10/06 20:29:28]

You need to clear this when ExtensionTabHelper goes away, otherwise you will
crash.

[asargent_no_longer_on_chrome, 2011/10/06 22:37:38]

delegate_ is a WeakPtr, so we get this for free. (The "if (delegate_)" check
will return false, because SupportsWeakPtr objects clear all their outstanding
WeakPtr's when they get deleted.) I could change this to "if (delegate_.get())"
if that makes it read more clearly though. 

[Aaron Boodman, 2011/10/06 22:40:26]

Oh, I missed that, OK. yeah, I do think it would be a teeny bit more clear with
.get(), but nbd.

+    delegate_->AppNotifyChannelSetupComplete(request_id_, channel_id, error);
+  Release(); // Matches AddRef in Start.
+}