Refactor: Make MediaCaptureDevicesDispatcher have pluggable handlers.

chrome/browser/media/tab_capture_access_handler.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 "chrome/browser/media/tab_capture_access_handler.h"
+
+#include "chrome/browser/media/media_capture_devices_dispatcher.h"
+#include "chrome/browser/media/media_stream_capture_indicator.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/web_contents.h"
+
+#if defined(ENABLE_EXTENSIONS)

[Sergey Ulanov, 2015/06/01 23:39:18]

This file doesn't need to be compiled when extensions are disabled. I.e. you can
put this file under chrome_browser_extensions_sources in the gyp file and remove
these ifdefs. 

[changbin, 2015/06/02 14:20:09]

Done.

+#include "chrome/browser/extensions/api/tab_capture/tab_capture_registry.h"
+#include "extensions/common/permissions/permissions_data.h"
+#endif
+
+TabCaptureAccessHandler::TabCaptureAccessHandler() {
+}
+
+TabCaptureAccessHandler::~TabCaptureAccessHandler() {
+}
+
+bool TabCaptureAccessHandler::SupportsStreamType(
+    const content::MediaStreamType type,
+    const extensions::Extension* extension) {
+  return type == content::MEDIA_TAB_VIDEO_CAPTURE ||
+         type == content::MEDIA_TAB_AUDIO_CAPTURE;
+}
+
+bool TabCaptureAccessHandler::CheckMediaAccessPermission(
+    content::WebContents* web_contents,
+    const GURL& security_origin,
+    content::MediaStreamType type,
+    const extensions::Extension* extension) {
+  return false;
+}
+
+void TabCaptureAccessHandler::HandleRequest(
+    content::WebContents* web_contents,
+    const content::MediaStreamRequest& request,
+    const content::MediaResponseCallback& callback,
+    const extensions::Extension* extension) {
+  content::MediaStreamDevices devices;
+  scoped_ptr<content::MediaStreamUI> ui;
+
+#if defined(ENABLE_EXTENSIONS)
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents->GetBrowserContext());
+  extensions::TabCaptureRegistry* tab_capture_registry =
+      extensions::TabCaptureRegistry::Get(profile);
+  if (!tab_capture_registry) {
+    NOTREACHED();
+    callback.Run(devices, content::MEDIA_DEVICE_INVALID_STATE, ui.Pass());
+    return;
+  }
+  const bool tab_capture_allowed = tab_capture_registry->VerifyRequest(
+      request.render_process_id, request.render_frame_id, extension->id());
+
+  if (request.audio_type == content::MEDIA_TAB_AUDIO_CAPTURE &&
+      tab_capture_allowed &&
+      extension->permissions_data()->HasAPIPermission(
+          extensions::APIPermission::kTabCapture)) {
+    devices.push_back(content::MediaStreamDevice(
+        content::MEDIA_TAB_AUDIO_CAPTURE, std::string(), std::string()));
+  }
+
+  if (request.video_type == content::MEDIA_TAB_VIDEO_CAPTURE &&
+      tab_capture_allowed &&
+      extension->permissions_data()->HasAPIPermission(
+          extensions::APIPermission::kTabCapture)) {
+    devices.push_back(content::MediaStreamDevice(
+        content::MEDIA_TAB_VIDEO_CAPTURE, std::string(), std::string()));
+  }
+
+  if (!devices.empty()) {
+    ui = MediaCaptureDevicesDispatcher::GetInstance()
+             ->GetMediaStreamCaptureIndicator()
+             ->RegisterMediaStream(web_contents, devices);
+  }
+  callback.Run(devices, devices.empty() ? content::MEDIA_DEVICE_INVALID_STATE
+                                        : content::MEDIA_DEVICE_OK,
+               ui.Pass());
+#else   // defined(ENABLE_EXTENSIONS)
+  callback.Run(devices, content::MEDIA_DEVICE_TAB_CAPTURE_FAILURE, ui.Pass());
+#endif  // defined(ENABLE_EXTENSIONS)
+}