Refactor: Make MediaCaptureDevicesDispatcher have pluggable handlers.

chrome/browser/media/permission_bubble_media_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/permission_bubble_media_access_handler.h"
+
+#include "base/metrics/field_trial.h"
+#include "chrome/browser/media/media_stream_device_permissions.h"
+#include "chrome/browser/media/media_stream_infobar_delegate.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/website_settings/permission_bubble_manager.h"
+#include "chrome/common/pref_names.h"
+#include "components/content_settings/core/browser/host_content_settings_map.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/browser/web_contents.h"
+
+using content::BrowserThread;
+
+namespace {
+
+// A finch experiment to enable the permission bubble for media requests only.
+bool MediaStreamPermissionBubbleExperimentEnabled() {
+  const std::string group =
+      base::FieldTrialList::FindFullName("MediaStreamPermissionBubble");
+  if (group == "enabled")
+    return true;
+
+  return false;
+}
+
+}  // namespace
+
+struct PermissionBubbleMediaAccessHandler::PendingAccessRequest {
+  PendingAccessRequest(const content::MediaStreamRequest& request,
+                       const content::MediaResponseCallback& callback)
+      : request(request), callback(callback) {}
+  ~PendingAccessRequest() {}
+
+  // TODO(gbillock): make the MediaStreamDevicesController owned by
+  // this object when we're using bubbles.
+  content::MediaStreamRequest request;
+  content::MediaResponseCallback callback;
+};
+
+PermissionBubbleMediaAccessHandler::PermissionBubbleMediaAccessHandler() {
+  // PermissionBubbleMediaAccessHandler should be created on UI thread.
+  // Otherwise, it will not receive
+  // content::NOTIFICATION_WEB_CONTENTS_DESTROYED, and that will result in
+  // possible use after free.
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  notifications_registrar_.Add(this,
+                               content::NOTIFICATION_WEB_CONTENTS_DESTROYED,
+                               content::NotificationService::AllSources());
+}
+
+PermissionBubbleMediaAccessHandler::~PermissionBubbleMediaAccessHandler() {
+}
+
+bool PermissionBubbleMediaAccessHandler::SupportsStreamType(
+    const content::MediaStreamType type,
+    const extensions::Extension* extension) {
+  return type == content::MEDIA_DEVICE_VIDEO_CAPTURE ||
+         type == content::MEDIA_DEVICE_AUDIO_CAPTURE;
+}
+
+bool PermissionBubbleMediaAccessHandler::CheckMediaAccessPermission(
+    content::WebContents* web_contents,
+    const GURL& security_origin,
+    content::MediaStreamType type,
+    const extensions::Extension* extension) {
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents->GetBrowserContext());
+
+  ContentSettingsType content_settings_type =
+      type == content::MEDIA_DEVICE_AUDIO_CAPTURE
+          ? CONTENT_SETTINGS_TYPE_MEDIASTREAM_MIC
+          : CONTENT_SETTINGS_TYPE_MEDIASTREAM_CAMERA;
+
+  if (CheckAllowAllMediaStreamContentForOrigin(profile, security_origin,
+                                               content_settings_type)) {
+    return true;
+  }
+
+  const char* policy_name = type == content::MEDIA_DEVICE_AUDIO_CAPTURE
+                                ? prefs::kAudioCaptureAllowed
+                                : prefs::kVideoCaptureAllowed;
+  const char* list_policy_name = type == content::MEDIA_DEVICE_AUDIO_CAPTURE
+                                     ? prefs::kAudioCaptureAllowedUrls
+                                     : prefs::kVideoCaptureAllowedUrls;
+  if (GetDevicePolicy(profile, security_origin, policy_name,
+                      list_policy_name) == ALWAYS_ALLOW) {
+    return true;
+  }
+
+  // There's no secondary URL for these content types, hence duplicating
+  // |security_origin|.
+  if (profile->GetHostContentSettingsMap()->GetContentSetting(
+          security_origin, security_origin, content_settings_type,
+          content_settings::ResourceIdentifier()) == CONTENT_SETTING_ALLOW) {
+    return true;
+  }
+
+  return false;
+}
+
+void PermissionBubbleMediaAccessHandler::HandleRequest(
+    content::WebContents* web_contents,
+    const content::MediaStreamRequest& request,
+    const content::MediaResponseCallback& callback,
+    const extensions::Extension* extension) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  RequestsQueue& queue = pending_requests_[web_contents];
+  queue.push_back(PendingAccessRequest(request, callback));
+
+  // If this is the only request then show the infobar.
+  if (queue.size() == 1)
+    ProcessQueuedAccessRequest(web_contents);
+}
+
+void PermissionBubbleMediaAccessHandler::ProcessQueuedAccessRequest(
+    content::WebContents* web_contents) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  std::map<content::WebContents*, RequestsQueue>::iterator it =
+      pending_requests_.find(web_contents);
+
+  if (it == pending_requests_.end() || it->second.empty()) {
+    // Don't do anything if the tab was closed.
+    return;
+  }
+
+  DCHECK(!it->second.empty());
+
+  if (PermissionBubbleManager::Enabled() ||
+      MediaStreamPermissionBubbleExperimentEnabled()) {
+    scoped_ptr<MediaStreamDevicesController> controller(
+        new MediaStreamDevicesController(
+            web_contents, it->second.front().request,
+            base::Bind(
+                &PermissionBubbleMediaAccessHandler::OnAccessRequestResponse,
+                base::Unretained(this), web_contents)));
+    if (controller->DismissInfoBarAndTakeActionOnSettings())
+      return;
+    PermissionBubbleManager* bubble_manager =
+        PermissionBubbleManager::FromWebContents(web_contents);
+    if (bubble_manager)
+      bubble_manager->AddRequest(controller.release());
+    return;
+  }
+
+  // TODO(gbillock): delete this block and the MediaStreamInfoBarDelegate
+  // when we've transitioned to bubbles. (crbug/337458)
+  MediaStreamInfoBarDelegate::Create(
+      web_contents, it->second.front().request,
+      base::Bind(&PermissionBubbleMediaAccessHandler::OnAccessRequestResponse,
+                 base::Unretained(this), web_contents));
+}
+
+void PermissionBubbleMediaAccessHandler::UpdateMediaRequestState(
+    int render_process_id,
+    int render_frame_id,
+    int page_request_id,
+    content::MediaStreamType stream_type,
+    content::MediaRequestState state) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  if (state != content::MEDIA_REQUEST_STATE_CLOSING)
+    return;
+
+  bool found = false;
+  for (RequestsQueues::iterator rqs_it = pending_requests_.begin();
+       rqs_it != pending_requests_.end(); ++rqs_it) {
+    RequestsQueue& queue = rqs_it->second;
+    for (RequestsQueue::iterator it = queue.begin(); it != queue.end(); ++it) {
+      if (it->request.render_process_id == render_process_id &&
+          it->request.render_frame_id == render_frame_id &&
+          it->request.page_request_id == page_request_id) {
+        queue.erase(it);
+        found = true;
+        break;
+      }
+    }
+    if (found)
+      break;
+  }
+}
+
+void PermissionBubbleMediaAccessHandler::OnAccessRequestResponse(
+    content::WebContents* web_contents,
+    const content::MediaStreamDevices& devices,
+    content::MediaStreamRequestResult result,
+    scoped_ptr<content::MediaStreamUI> ui) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  std::map<content::WebContents*, RequestsQueue>::iterator it =
+      pending_requests_.find(web_contents);
+  if (it == pending_requests_.end()) {
+    // WebContents has been destroyed. Don't need to do anything.
+    return;
+  }
+
+  RequestsQueue& queue(it->second);
+  if (queue.empty())
+    return;
+
+  content::MediaResponseCallback callback = queue.front().callback;
+  queue.pop_front();
+
+  if (!queue.empty()) {
+    // Post a task to process next queued request. It has to be done
+    // asynchronously to make sure that calling infobar is not destroyed until
+    // after this function returns.
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(
+            &PermissionBubbleMediaAccessHandler::ProcessQueuedAccessRequest,
+            base::Unretained(this), web_contents));
+  }
+
+  callback.Run(devices, result, ui.Pass());
+}
+
+void PermissionBubbleMediaAccessHandler::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  if (type == content::NOTIFICATION_WEB_CONTENTS_DESTROYED) {
+    content::WebContents* web_contents =
+        content::Source<content::WebContents>(source).ptr();
+    pending_requests_.erase(web_contents);
+  }
+}