refactor EnumerateDevices to make it a persistent request.

content/common/media/media_stream_options.cc

Index: content/common/media/media_stream_options.cc
===================================================================
--- content/common/media/media_stream_options.cc	(revision 148913)
+++ content/common/media/media_stream_options.cc	(working copy)
@@ -24,4 +24,12 @@
       in_use(opened),
       session_id(kNoId) {}
 
+bool StreamDeviceInfo::operator==(const StreamDeviceInfo& other) const {

[tommi (sloooow) - chröme, 2012/08/03 09:10:35]

nit: Change this method to IsEqual() (we don't override operators except for
special cases)

[wjia(left Chromium), 2012/08/03 21:53:45]

This overloading is needed for StreamDeviceInfoArray which is typedef'ed as
std::vector<StreamDeviceInfo>. In MediaStreamManager::DevicesEnumerated, the
incoming devices are compared against cached devices.

[tommi (sloooow) - chröme, 2012/08/04 09:27:08]

You can use std::equal instead.  See for example:
http://code.google.com/searchframe#OAMlx_jo-ck/src/chrome/browser/policy/poli...

[wjia(left Chromium), 2012/08/07 23:16:34]

Done.

+  return stream_type == other.stream_type &&
+      name == other.name &&
+      device_id == other.device_id &&
+      in_use == other.in_use &&
+      session_id == other.session_id;
+}
+
 }  // namespace media_stream