support video device enumeration from renderer process.

content/browser/renderer_host/media/video_capture_manager.cc

Index: content/browser/renderer_host/media/video_capture_manager.cc
===================================================================
--- content/browser/renderer_host/media/video_capture_manager.cc	(revision 109718)
+++ content/browser/renderer_host/media/video_capture_manager.cc	(working copy)
@@ -4,6 +4,8 @@
 
 #include "content/browser/renderer_host/media/video_capture_manager.h"
 
+#include <set>
+
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "content/browser/renderer_host/media/video_capture_controller.h"
@@ -51,12 +53,14 @@
   // Temporary solution: close all open devices and delete them, after the
   // thread is stopped.
   DLOG_IF(ERROR, !devices_.empty()) << "VideoCaptureManager: Open devices!";
+  std::set<media::VideoCaptureDevice*> devices_to_delete;
   for (VideoCaptureDevices::iterator it = devices_.begin();
        it != devices_.end();
        ++it) {
     it->second->DeAllocate();
-    delete it->second;
+    devices_to_delete.insert(it->second);
   }
+  STLDeleteElements(&devices_to_delete);
   STLDeleteValues(&controllers_);
 }