Fix gn_all build on gcc 4.8

chrome/browser/media/webrtc/media_stream_devices_controller.h

 // 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.
 
 #ifndef CHROME_BROWSER_MEDIA_WEBRTC_MEDIA_STREAM_DEVICES_CONTROLLER_H_
 #define CHROME_BROWSER_MEDIA_WEBRTC_MEDIA_STREAM_DEVICES_CONTROLLER_H_
 
 #include <map>
 #include <string>
 
 #include "base/macros.h"
 #include "chrome/browser/permissions/permission_request.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "content/public/browser/web_contents_delegate.h"
 
+class MediaStreamDevicesController;
 class Profile;
 class TabSpecificContentSettings;
 
 namespace content {
 class WebContents;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace policy {
 class MediaStreamDevicesControllerBrowserTest;
 }
 
 namespace test {
 class MediaStreamDevicesControllerTestApi;
 }
 
+namespace internal {
+// Delegate showing permission prompts.

[sky, 2017/03/23 22:59:46]

Why does this need to move? What error happens with it in the private section of
the class?

[Tom (Use chromium acct), 2017/03/23 23:45:14]

Subclasses cannot derive from PermissionPromptDelegate (even if they are friend
classes) on gcc.

In file included from
../../chrome/browser/permissions/permission_request_manager_browsertest.cc:13:0:
../../chrome/browser/media/webrtc/media_stream_devices_controller.h:78:9: error:
'class MediaStreamDevicesController::PermissionPromptDelegate' is private
   class PermissionPromptDelegate {
         ^
../../chrome/browser/permissions/permission_request_manager_browsertest.cc:32:44:
error: within this context
     : public MediaStreamDevicesController::PermissionPromptDelegate {

+class PermissionPromptDelegate {
+ public:
+  virtual void ShowPrompt(
+      bool user_gesture,
+      content::WebContents* web_contents,
+      std::unique_ptr<MediaStreamDevicesController> controller) = 0;
+};
+}
+
 class MediaStreamDevicesController : public PermissionRequest {
  public:
   static void RequestPermissions(
       content::WebContents* web_contents,
       const content::MediaStreamRequest& request,
       const content::MediaResponseCallback& callback);
 
   // Registers the prefs backing the audio and video policies.
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
@@ skipping 22 matching lines @@
   void PermissionDenied() override;
   void Cancelled() override;
   void RequestFinished() override;
   PermissionRequestType GetPermissionRequestType() const override;
 
  private:
   friend class MediaStreamDevicesControllerTest;
   friend class test::MediaStreamDevicesControllerTestApi;
   friend class policy::MediaStreamDevicesControllerBrowserTest;
 
-  // Delegate showing permission prompts.
-  class PermissionPromptDelegate {
-   public:
-    virtual void ShowPrompt(
-        bool user_gesture,
-        content::WebContents* web_contents,
-        std::unique_ptr<MediaStreamDevicesController> controller) = 0;
-  };
-
   class MediaPermissionStatus;
   class PermissionPromptDelegateImpl;
 
   static void RequestPermissionsWithDelegate(
       content::WebContents* web_contents,
       const content::MediaStreamRequest& request,
       const content::MediaResponseCallback& callback,
-      PermissionPromptDelegate* delegate);
+      internal::PermissionPromptDelegate* delegate);
 
   MediaStreamDevicesController(content::WebContents* web_contents,
                                const content::MediaStreamRequest& request,
                                const content::MediaResponseCallback& callback,
                                const MediaPermissionStatus& initial_permission);
 
   bool IsAllowedForAudio() const;
   bool IsAllowedForVideo() const;
 
   // Returns a list of devices available for the request for the given
@@ skipping 54 matching lines @@
   // was created.
   TabSpecificContentSettings* content_settings_;
 
   // The original request for access to devices.
   const content::MediaStreamRequest request_;
 
   // The callback that needs to be Run to notify WebRTC of whether access to
   // audio/video devices was granted or not.
   content::MediaResponseCallback callback_;
 
-  std::unique_ptr<PermissionPromptDelegate> delegate_;
+  std::unique_ptr<internal::PermissionPromptDelegate> delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamDevicesController);
 };
 
 #endif  // CHROME_BROWSER_MEDIA_WEBRTC_MEDIA_STREAM_DEVICES_CONTROLLER_H_