Add content API for requesting the current geolocation

content/browser/geolocation/geolocation.cc

 // Copyright (c) 2012 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 "content/public/browser/geolocation.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
+#include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop_proxy.h"
 #include "content/browser/geolocation/geolocation_provider.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/geoposition.h"
 
 namespace content {
 
 namespace {
 
 void OverrideLocationForTestingOnIOThread(
     const Geoposition& position,
     const base::Closure& completion_callback,
     scoped_refptr<base::MessageLoopProxy> callback_loop) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   GeolocationProvider::GetInstance()->OverrideLocationForTesting(position);
   callback_loop->PostTask(FROM_HERE, completion_callback);
 }
 
+void GeolocationUpdateCallbackOnIOThread(
+    const GeolocationUpdateCallback& client_callback,
+    scoped_refptr<base::MessageLoopProxy> client_loop,
+    const Geoposition& position) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (base::MessageLoopProxy::current() != client_loop)
+    client_loop->PostTask(FROM_HERE, base::Bind(client_callback, position));
+  else
+    client_callback.Run(position);
+}
+
+void RequestLocationUpdateOnIOThread(
+    const GeolocationUpdateCallback& client_callback,
+    scoped_refptr<base::MessageLoopProxy> client_loop) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  GeolocationUpdateCallback io_thread_callback = base::Bind(
+      &GeolocationUpdateCallbackOnIOThread,
+      client_callback,
+      client_loop);
+  GeolocationProvider::GetInstance()->RequestCallback(io_thread_callback);
+}
+
 }  // namespace
 
 void OverrideLocationForTesting(
     const Geoposition& position,
     const base::Closure& completion_callback) {
   base::Closure closure = base::Bind(&OverrideLocationForTestingOnIOThread,
                                      position,
                                      completion_callback,
                                      base::MessageLoopProxy::current());
-  if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::IO))
     BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, closure);
-  } else {
+  else
     closure.Run();
-  }
+}
+
+void RequestLocationUpdate(const GeolocationUpdateCallback& callback) {
+  base::Closure closure = base::Bind(&RequestLocationUpdateOnIOThread,
+                                     callback,
+                                     base::MessageLoopProxy::current());
+  if (!BrowserThread::CurrentlyOn(BrowserThread::IO))
+    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, closure);
+  else
+    closure.Run();
 }
 
 }  // namespace content