Implement CancelUserMediaRequest for the browser part

content/browser/renderer_host/media/media_stream_manager.cc

Index: content/browser/renderer_host/media/media_stream_manager.cc
diff --git a/content/browser/renderer_host/media/media_stream_manager.cc b/content/browser/renderer_host/media/media_stream_manager.cc
index ca2d285041f88865e24470dc3ccf408c76d8744b..36fa28662a7f205615c37dca2fd37634a40abaf2 100644
--- a/content/browser/renderer_host/media/media_stream_manager.cc
+++ b/content/browser/renderer_host/media/media_stream_manager.cc
@@ -214,6 +214,16 @@ void MediaStreamManager::CancelRequests(MediaStreamRequester* requester) {
   }
 }
 
+void MediaStreamManager::CancelGeneratedStream(const std::string& label) {

[wjia(left Chromium), 2012/06/06 06:18:21]

This would be MediaStreamManager::CancelGenerateStream.

Since this function could be called at any time during a stream is generated and
there are multiple steps to generate a stream, it would be great to take care
all cases. For example, this function is called when user has granted access
permission and device managers are trying to open devices. This patch takes care
of the case in which user has not granted access permission yet.

+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  DeviceRequests::iterator it = requests_.find(label);
+  if (it != requests_.end()) {
+    device_settings_->RemovePendingCaptureRequest(label);
+    requests_.erase(it);
+  }
+}
+
 void MediaStreamManager::StopGeneratedStream(const std::string& label) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   // Find the request and close all open devices for the request.