Pepper: Access PepperMediaDeviceManager through a WeakPtr

content/renderer/pepper/pepper_device_enumeration_host_helper.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/renderer/pepper/pepper_device_enumeration_host_helper.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 28 matching lines @@
     requested_ = true;
 
     // Note that the callback passed into
     // PepperDeviceEnumerationHostHelper::Delegate::EnumerateDevices() may be
     // called synchronously. In that case, |request_id_| hasn't been updated
     // when the callback is called. Moreover, |callback| may destroy this
     // object. So we don't pass in |callback| directly. Instead, we use
     // EnumerateDevicesCallbackBody() to ensure that we always call |callback|
     // asynchronously.
     sync_call_ = true;
+    DCHECK(owner_->delegate_);
     request_id_ = owner_->delegate_->EnumerateDevices(
         owner_->device_type_,
         owner_->document_url_,
         base::Bind(&ScopedRequest::EnumerateDevicesCallbackBody, AsWeakPtr()));
     sync_call_ = false;
   }
 
   ~ScopedRequest() {
-    if (requested_) {
+    if (requested_ && owner_->delegate_) {
       owner_->delegate_->StopEnumerateDevices(request_id_);
     }
   }
 
   bool requested() const { return requested_; }
 
  private:
   void EnumerateDevicesCallbackBody(
       int request_id,
       const std::vector<ppapi::DeviceRefData>& devices) {
@@ skipping 16 matching lines @@
       callback_;
   bool requested_;
   int request_id_;
   bool sync_call_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedRequest);
 };
 
 PepperDeviceEnumerationHostHelper::PepperDeviceEnumerationHostHelper(
     ppapi::host::ResourceHost* resource_host,
-    Delegate* delegate,
+    base::WeakPtr<Delegate> delegate,
     PP_DeviceType_Dev device_type,
     const GURL& document_url)
     : resource_host_(resource_host),
       delegate_(delegate),
       device_type_(device_type),
       document_url_(document_url) {}
 
 PepperDeviceEnumerationHostHelper::~PepperDeviceEnumerationHostHelper() {}
 
 bool PepperDeviceEnumerationHostHelper::HandleResourceMessage(
@@ skipping 77 matching lines @@
     uint32_t callback_id,
     int /* request_id */,
     const std::vector<ppapi::DeviceRefData>& devices) {
   resource_host_->host()->SendUnsolicitedReply(
       resource_host_->pp_resource(),
       PpapiPluginMsg_DeviceEnumeration_NotifyDeviceChange(callback_id,
                                                           devices));
 }
 
 }  // namespace content