Refactor media permission dispatcher class and create proxy class for non-UI threads.

content/renderer/media/media_permission_dispatcher_impl.cc

 // Copyright 2015 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/renderer/media/media_permission_dispatcher.h"
+#include "content/renderer/media/media_permission_dispatcher_impl.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
+#include "base/thread_task_runner_handle.h"
 #include "content/public/common/service_registry.h"
 #include "content/public/renderer/render_frame.h"
+#include "content/renderer/media/media_permission_dispatcher_proxy.h"
 #include "third_party/WebKit/public/web/WebUserGestureIndicator.h"
 #include "url/gurl.h"
 
 namespace {
 
 using Type = media::MediaPermission::Type;
 
 content::PermissionName MediaPermissionTypeToPermissionName(Type type) {
   switch (type) {
     case Type::PROTECTED_MEDIA_IDENTIFIER:
       return content::PERMISSION_NAME_PROTECTED_MEDIA_IDENTIFIER;
     case Type::AUDIO_CAPTURE:
       return content::PERMISSION_NAME_AUDIO_CAPTURE;
     case Type::VIDEO_CAPTURE:
       return content::PERMISSION_NAME_VIDEO_CAPTURE;
   }
   NOTREACHED();
   return content::PERMISSION_NAME_PROTECTED_MEDIA_IDENTIFIER;
 }
 
 }  // namespace
 
 namespace content {
 
-MediaPermissionDispatcher::MediaPermissionDispatcher(RenderFrame* render_frame)
-    : RenderFrameObserver(render_frame), next_request_id_(0) {
+MediaPermissionDispatcherImpl::MediaPermissionDispatcherImpl(
+    RenderFrame* render_frame)
+    : RenderFrameObserver(render_frame),
+      task_runner_(base::ThreadTaskRunnerHandle::Get()) {}
+
+MediaPermissionDispatcherImpl::~MediaPermissionDispatcherImpl() {
+  DCHECK(thread_checker_.CalledOnValidThread());
 }
 
-MediaPermissionDispatcher::~MediaPermissionDispatcher() {
-  DCHECK(thread_checker_.CalledOnValidThread());
-
-  // Fire all pending callbacks with |false|.
-  for (auto& request : requests_)
-    request.second.Run(false);
-
-  requests_.clear();
-}
-
-void MediaPermissionDispatcher::HasPermission(
+void MediaPermissionDispatcherImpl::HasPermission(
     Type type,
     const GURL& security_origin,
     const PermissionStatusCB& permission_status_cb) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (!permission_service_.get()) {
     render_frame()->GetServiceRegistry()->ConnectToRemoteService(
         mojo::GetProxy(&permission_service_));
   }
 
-  uint32_t request_id = next_request_id_++;
-  DCHECK(!requests_.count(request_id));
-  requests_[request_id] = permission_status_cb;
-
-  DVLOG(2) << __FUNCTION__ << ": request ID " << request_id;
-
   permission_service_->HasPermission(
       MediaPermissionTypeToPermissionName(type), security_origin.spec(),
-      base::Bind(&MediaPermissionDispatcher::OnPermissionStatus,
-                 base::Unretained(this), request_id));
+      base::Bind(&MediaPermissionDispatcherImpl::OnPermissionStatus,
+                 base::Unretained(this),

[perkj_chrome, 2015/09/22 08:24:16]

Why is it safe to use Unretained?  Looks scary to me. Why not use weakptr? 

[guoweis_left_chromium, 2015/09/22 18:48:49]

Done.

+                 RegisterCallback(permission_status_cb)));
 }
 
-void MediaPermissionDispatcher::RequestPermission(
+void MediaPermissionDispatcherImpl::RequestPermission(
     Type type,
     const GURL& security_origin,
     const PermissionStatusCB& permission_status_cb) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (!permission_service_.get()) {
     render_frame()->GetServiceRegistry()->ConnectToRemoteService(
         mojo::GetProxy(&permission_service_));
   }
 
-  uint32_t request_id = next_request_id_++;
-  DCHECK(!requests_.count(request_id));
-  requests_[request_id] = permission_status_cb;
-
-  DVLOG(2) << __FUNCTION__ << ": request ID " << request_id;
-
   permission_service_->RequestPermission(
       MediaPermissionTypeToPermissionName(type), security_origin.spec(),
       blink::WebUserGestureIndicator::isProcessingUserGesture(),
-      base::Bind(&MediaPermissionDispatcher::OnPermissionStatus,
-                 base::Unretained(this), request_id));
+      base::Bind(&MediaPermissionDispatcherImpl::OnPermissionStatus,
+                 base::Unretained(this),
+                 RegisterCallback(permission_status_cb)));
 }
 
-void MediaPermissionDispatcher::OnPermissionStatus(uint32_t request_id,
-                                                   PermissionStatus status) {
-  DVLOG(2) << __FUNCTION__ << ": (" << request_id << ", " << status << ")";
+scoped_ptr<media::MediaPermission> MediaPermissionDispatcherImpl::CreateProxy(
+    scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner) {
+  scoped_ptr<media::MediaPermission> media_permission_proxy(
+      new MediaPermissionDispatcherProxy(task_runner_, caller_task_runner,
+                                         base::AsWeakPtr(this)));
+  return media_permission_proxy.Pass();
+}
+
+void MediaPermissionDispatcherImpl::OnPermissionStatus(
+    uint32_t request_id,
+    PermissionStatus status) {
   DCHECK(thread_checker_.CalledOnValidThread());
-
-  RequestMap::iterator iter = requests_.find(request_id);
-  if (iter == requests_.end()) {
-    DVLOG(2) << "Request not found.";
-    return;
-  }
-
-  PermissionStatusCB permission_status_cb = iter->second;
-  requests_.erase(iter);
-
-  permission_status_cb.Run(status == PERMISSION_STATUS_GRANTED);
+  DeliverResult(request_id, status == PERMISSION_STATUS_GRANTED);
 }
 
 }  // namespace content