<webview>: First stab at implementing media permission request for guests.

content/renderer/browser_plugin/browser_plugin.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/browser_plugin/browser_plugin.h"
 
 #include "base/json/json_string_value_serializer.h"
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
@@ skipping 80 matching lines @@
       persist_storage_(false),
       valid_partition_id_(true),
       content_window_routing_id_(MSG_ROUTING_NONE),
       plugin_focused_(false),
       visible_(true),
       size_changed_in_flight_(false),
       allocate_instance_id_sent_(false),
       browser_plugin_manager_(render_view->browser_plugin_manager()),
       current_nav_entry_index_(0),
       nav_entry_count_(0),
-      compositing_enabled_(false) {
+      compositing_enabled_(false),
+      ALLOW_THIS_IN_INITIALIZER_LIST(
+          weak_ptr_factory_(this)) {
   bindings_.reset(new BrowserPluginBindings(this));
 }
 
 BrowserPlugin::~BrowserPlugin() {
   // If the BrowserPlugin has never navigated then the browser process and
   // BrowserPluginManager don't know about it and so there is nothing to do
   // here.
   if (!navigate_src_sent_)
     return;
   browser_plugin_manager()->RemoveBrowserPlugin(instance_id_);
@@ skipping 10 matching lines @@
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_GuestContentWindowReady,
                         OnGuestContentWindowReady)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_GuestGone, OnGuestGone)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_GuestResponsive, OnGuestResponsive)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_GuestUnresponsive, OnGuestUnresponsive)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_LoadAbort, OnLoadAbort)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_LoadCommit, OnLoadCommit)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_LoadRedirect, OnLoadRedirect)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_LoadStart, OnLoadStart)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_LoadStop, OnLoadStop)
+    IPC_MESSAGE_HANDLER(BrowserPluginMsg_RequestPermission, OnRequestPermission)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_SetCursor, OnSetCursor)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_ShouldAcceptTouchEvents,
                         OnShouldAcceptTouchEvents)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_UpdatedName, OnUpdatedName)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_UpdateRect, OnUpdateRect)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
@@ skipping 238 matching lines @@
       new BrowserPluginHostMsg_CreateGuest(render_view_routing_id_,
                                            instance_id_,
                                            create_guest_params));
 
   // Record that we sent a navigation request to the browser process.
   // Once this instance has navigated, the storage partition cannot be changed,
   // so this value is used for enforcing this.
   navigate_src_sent_ = true;
 }
 
+void BrowserPlugin::PopulateAncestorList() {
+  if (!container())
+    return;
+
+  WebKit::WebNode ancestor = container()->element();
+  // Escape the <webview> shim if this BrowserPlugin has one.
+  WebKit::WebElement shim = ancestor.shadowHost();
+  if (!shim.isNull())
+    ancestor = shim;
+  ancestors_.clear();
+  while (!ancestor.isNull()) {
+    ancestors_.push_back(ancestor);
+    ancestor = ancestor.parentNode();
+  }
+}
+
 void BrowserPlugin::OnAdvanceFocus(int instance_id, bool reverse) {
   DCHECK(render_view_);
   render_view_->GetWebView()->advanceFocus(reverse);
 }
 
 void BrowserPlugin::OnBuffersSwapped(int instance_id,
                                      const gfx::Size& size,
                                      std::string mailbox_name,
                                      int gpu_route_id,
                                      int gpu_host_id) {
@@ skipping 101 matching lines @@
   props[browser_plugin::kURL] = new base::StringValue(url.spec());
   props[browser_plugin::kIsTopLevel] = new base::FundamentalValue(is_top_level);
 
   TriggerEvent(browser_plugin::kEventLoadStart, &props);
 }
 
 void BrowserPlugin::OnLoadStop(int instance_id) {
   TriggerEvent(browser_plugin::kEventLoadStop, NULL);
 }
 
+void BrowserPlugin::OnRequestPermission(
+    int instance_id,
+    const std::string& permission_type,
+    int request_id,
+    const base::DictionaryValue& request_info) {
+  if (permission_type == browser_plugin::kPermissionTypeMedia)
+    RequestMediaPermission(request_id, request_info);
+}
+
 void BrowserPlugin::OnSetCursor(int instance_id, const WebCursor& cursor) {
   cursor_ = cursor;
 }
 
 void BrowserPlugin::OnShouldAcceptTouchEvents(int instance_id, bool accept) {
   if (container()) {
     container()->requestTouchEventType(accept ?
         WebKit::WebPluginContainer::TouchEventRequestTypeRaw :
         WebKit::WebPluginContainer::TouchEventRequestTypeNone);
   }
 }
 
 void BrowserPlugin::OnUpdatedName(int instance_id, const std::string& name) {
   UpdateDOMAttribute(browser_plugin::kAttributeName, name);
 }
 
+void BrowserPlugin::RequestMediaPermission(
+    int request_id, const base::DictionaryValue& request_info) {
+  if (!HasEventListeners(browser_plugin::kEventRequestPermission)) {
+    // Automatically deny the request if there are no event listeners for
+    // permissionrequest.
+    AllowPermission(BrowserPlugin::MEDIA, request_id, false /* allow */);
+    return;
+  }
+  DCHECK(!pending_permission_requests_.count(request_id));
+  pending_permission_requests_.insert(
+      std::make_pair(request_id,
+                     std::make_pair(request_id, BrowserPlugin::MEDIA)));
+
+  std::map<std::string, base::Value*> props;
+  props[browser_plugin::kPermission] =
+      base::Value::CreateStringValue(browser_plugin::kPermissionTypeMedia);
+  props[browser_plugin::kRequestId] =
+      base::Value::CreateIntegerValue(request_id);
+
+  // Fill in the info provided by the browser.
+  for (DictionaryValue::Iterator iter(request_info); !iter.IsAtEnd();
+           iter.Advance()) {
+    props[iter.key()] = iter.value().DeepCopy();
+  }
+  TriggerEvent(browser_plugin::kEventRequestPermission, &props);
+}
+
+bool BrowserPlugin::HasEventListeners(const std::string& event_name) {
+  if (!container())
+    return false;
+
+  for (size_t i = 0; i < ancestors_.size(); ++i) {
+    if (ancestors_[i].hasEventListeners(
+            WebKit::WebString::fromUTF8(event_name))) {
+      return true;
+    }
+  }
+  return false;
+}
+
 void BrowserPlugin::OnUpdateRect(
     int instance_id,
     const BrowserPluginMsg_UpdateRect_Params& params) {
   bool use_new_damage_buffer = !backing_store_;
   BrowserPluginHostMsg_AutoSize_Params auto_size_params;
   BrowserPluginHostMsg_ResizeGuest_Params resize_guest_params;
   // If we have a pending damage buffer, and the guest has begun to use the
   // damage buffer then we know the guest will no longer use the current
   // damage buffer. At this point, we drop the current damage buffer, and
   // mark the pending damage buffer as the current damage buffer.
@@ skipping 227 matching lines @@
   // wrapper/shim (e.g. <webview> tag) should receive these events, and expose a
   // more appropriate (and stable) event to the consumers as part of the API.
   event.initCustomEvent(
       WebKit::WebString::fromUTF8(GetInternalEventName(event_name.c_str())),
       false, false,
       WebKit::WebSerializedScriptValue::serialize(
           v8::String::New(json_string.c_str(), json_string.size())));
   container()->element().dispatchEvent(event);
 }
 
+void BrowserPlugin::OnRequestObjectGarbageCollected(int request_id) {
+  // Remove from alive objects.
+  std::map<int, AliveV8PermissionRequestItem*>::iterator iter =
+      alive_v8_permission_request_objects.find(request_id);
+  if (iter != alive_v8_permission_request_objects.end()) {
+    DCHECK(iter->second->first == request_id);
+    alive_v8_permission_request_objects.erase(iter);
+  }
+
+  // If a decision has not been made for this request yet, deny it.
+  AllowPermissionIfRequestIsPending(request_id, false /*allow*/);
+}
+
+void BrowserPlugin::PersistRequestObject(
+    const NPVariant* request, const std::string& type, int id) {
+  DCHECK(alive_v8_permission_request_objects.find(id) ==
+      alive_v8_permission_request_objects.end());
+  if (alive_v8_permission_request_objects.find(id) !=
+      alive_v8_permission_request_objects.end()) {
+    return;

[abarth-chromium, 2013/02/14 18:56:53]

Why do you both DCHECK and handle this case?  It seems like you should do one or
the other but not both.

[lazyboy, 2013/02/14 21:47:20]

The if () {...} part is what we want, so a request to persist an object more
than once is ignored. If javascript accidentally calls this > once then we fail
on debug build so we can catch potential implementation bugs. (This is expected
to be called once). Is this a bad practice? I think I've seen code in chromium
using this pattern.

+  }
+  if (pending_permission_requests_.find(id) ==
+      pending_permission_requests_.end()) {
+    return;
+  }
+
+  v8::Persistent<v8::Value> weak_request =
+      v8::Persistent<v8::Value>::New(WebKit::WebBindings::toV8Value(request));
+
+  AliveV8PermissionRequestItem* new_item =
+      new std::pair<int, base::WeakPtr<BrowserPlugin> >(
+          id, weak_ptr_factory_.GetWeakPtr());
+
+  std::pair<std::map<int, AliveV8PermissionRequestItem*>::iterator, bool>
+      result = alive_v8_permission_request_objects.insert(
+          std::make_pair(id, new_item));
+  DCHECK(result.second);  // Inserted in the map.
+  if (result.second) {

[abarth-chromium, 2013/02/14 18:56:53]

Again, you're handling the case of the DCHECK failing.  In this case, you'll
create a big memory leak.  It's better to crash and get stack traces.  Perhaps
we should use CHECK rather than DCHECK?

[lazyboy, 2013/02/14 21:47:20]

CHECK is good here.
Done.

+    AliveV8PermissionRequestItem* request_item = result.first->second;
+    weak_request.MakeWeak(request_item, WeakCallbackForPersistObject);
+  }
+}
+
+// static
+void BrowserPlugin::WeakCallbackForPersistObject(
+    v8::Persistent<v8::Value> object, void* param) {
+  v8::Persistent<v8::Object> persistent_object =
+      v8::Persistent<v8::Object>::Cast(object);
+
+  AliveV8PermissionRequestItem* item_ptr =
+      static_cast<AliveV8PermissionRequestItem*>(param);
+  int request_id = item_ptr->first;
+  base::WeakPtr<BrowserPlugin> plugin = item_ptr->second;
+  if (plugin)
+    plugin->OnRequestObjectGarbageCollected(request_id);
+  delete item_ptr;
+
+  persistent_object.Dispose();

[abarth-chromium, 2013/02/14 18:56:53]

We usually call Clear() too.  I'm not sure if that's needed.

An important thing to know about these weak callbacks is that they can happen
any time GC runs, which can be any time you're inside V8.  That means you need
to be prepared for re-entrancy.  In particular, OnRequestObjectGarbageCollected
looks like it modifies a map.  That means you can never enter V8 while you're
iterating that map.  Otherwise, you might trigger GC and invalidate the map.

[lazyboy, 2013/02/14 21:47:20]

Added Clear().
Made OnRequestObjectGarbaggeCollected async.

+}
+
 void BrowserPlugin::Back() {
   if (!navigate_src_sent_)
     return;
   browser_plugin_manager()->Send(
       new BrowserPluginHostMsg_Go(render_view_routing_id_,
                                   instance_id_, -1));
 }
 
 void BrowserPlugin::Forward() {
   if (!navigate_src_sent_)
@@ skipping 50 matching lines @@
   bool embedder_focused = false;
   if (render_view_)
     embedder_focused = render_view_->has_focus();
   return plugin_focused_ && embedder_focused;
 }
 
 WebKit::WebPluginContainer* BrowserPlugin::container() const {
   return container_;
 }
 
+void BrowserPlugin::AllowPermission(
+    BrowserPlugin::PermissionRequestType type, int request_id, bool allow) {
+  switch (type) {
+    case BrowserPlugin::MEDIA:
+      browser_plugin_manager()->Send(
+          new BrowserPluginHostMsg_AllowPermission(
+              render_view_->GetRoutingID(), instance_id_,
+              browser_plugin::kPermissionTypeMedia, request_id, allow));
+      break;
+    case BrowserPlugin::INVALID:
+    default:
+      LOG(INFO) << "Not a valid permission type";
+      break;
+  }
+}
+
+void BrowserPlugin::AllowPermissionIfRequestIsPending(
+    int request_id, bool allow) {
+  PendingPermissionRequests::iterator iter =
+      pending_permission_requests_.find(request_id);
+  if (iter == pending_permission_requests_.end())
+    return;
+
+  BrowserPlugin::PermissionRequestType type = iter->second.second;
+  pending_permission_requests_.erase(iter);
+  AllowPermission(type, request_id, allow);
+}
+
+void BrowserPlugin::OnEmbedderDecidedPermission(int request_id, bool allow) {
+  AllowPermissionIfRequestIsPending(request_id, allow);
+}
+
 bool BrowserPlugin::initialize(WebPluginContainer* container) {
   container_ = container;
   container_->setWantsWheelEvents(true);
+  // This ancestor set is valid for the lifetime of BrowserPlugin as this object
+  // does not survive reparenting in the DOM tree.
+  PopulateAncestorList();
   ParseAttributes();
   return true;
 }
 
 void BrowserPlugin::EnableCompositing(bool enable) {
   if (compositing_enabled_ == enable)
     return;
 
   compositing_enabled_ = enable;
   if (enable) {
@@ skipping 300 matching lines @@
                                                  void* notify_data) {
 }
 
 void BrowserPlugin::didFailLoadingFrameRequest(
     const WebKit::WebURL& url,
     void* notify_data,
     const WebKit::WebURLError& error) {
 }
 
 }  // namespace content