Refactor lifetime management of UserMediaController

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

Index: third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
index e71cc2e5605c65124dcb65cca79de0d979828dd2..1462506f64d43f8ed8c1b3289b4f3d744c3f06b1 100644
--- a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
+++ b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
@@ -1424,7 +1424,6 @@ WebLocalFrameImpl::WebLocalFrameImpl(WebTreeScopeType scope, WebFrameClient* cli
     , m_autofillClient(0)
     , m_contentSettingsClient(0)
     , m_inputEventsScaleFactorForEmulation(1)
-    , m_userMediaClientImpl(this)
     , m_webDevToolsFrontend(0)
     , m_selfKeepAlive(this)
 {
@@ -1468,7 +1467,7 @@ void WebLocalFrameImpl::setCoreFrame(LocalFrame* frame)
         providePushControllerTo(*m_frame, m_client->pushClient());
 
     provideNotificationPermissionClientTo(*m_frame, NotificationPermissionClientImpl::create());
-    provideUserMediaTo(*m_frame, &m_userMediaClientImpl);
+    provideUserMediaTo(*m_frame, UserMediaClientImpl::create(m_client->userMediaClient()));

[dcheng, 2016/08/17 02:32:47]

Can m_client be null here? It's hard to tell.

(Personally, I'm not sure if we should allow WebLocalFrame to be created with a
null client, it seems to lead to more problems than it solves...)

[haraken, 2016/08/17 02:41:27]

Yeah, as far as I look at line 1466 and line 1480 etc, m_client can be null.

However, m_client can be null only after WebLocalFrameImpl::close() is called?
If that's the case, we won't need to instantiate these supplement objects in the
first place...

I'll look into more details.

     provideIndexedDBClientTo(*m_frame, IndexedDBClientImpl::create());
     provideLocalFileSystemTo(*m_frame, LocalFileSystemClient::create());
     provideNavigatorContentUtilsTo(*m_frame, NavigatorContentUtilsClientImpl::create(this));