Ensures that WebRTC works for device selection using a different sample rate than default

content/public/common/media_stream_request.h

Index: content/public/common/media_stream_request.h
diff --git a/content/public/common/media_stream_request.h b/content/public/common/media_stream_request.h
index e50d4e91a2d74bf9e81a53c5d4b34778f8a53dde..57e08975d97472a30a476e6c5f13cd94e8283413 100644
--- a/content/public/common/media_stream_request.h
+++ b/content/public/common/media_stream_request.h
@@ -53,6 +53,13 @@ struct CONTENT_EXPORT MediaStreamDevice {
       const std::string& id,
       const std::string& name);
 
+  MediaStreamDevice(
+      MediaStreamType type,
+      const std::string& id,
+      const std::string& name,
+      int sample_rate,

[Jói, 2013/01/15 22:30:20]

Document what the defaults for sample_rate and channel_layout are if you use the
3-param constructor.

[henrika (OOO until Aug 14), 2013/01/16 16:37:17]

Done.

+      int channel_layout);
+
   ~MediaStreamDevice();
 
   // The device's type.
@@ -63,6 +70,16 @@ struct CONTENT_EXPORT MediaStreamDevice {
 
   // The device's "friendly" name. Not guaranteed to be unique.
   std::string name;
+
+  // Preferred sample rate in samples per second for the device.
+  // Only utilized for audio devices.
+  int sample_rate;

[Jói, 2013/01/15 22:30:20]

Are the new struct members (sample_rate, channel_layout) going to be accessed
from outside of content?  If not, could they be added in a subclass of this
(after first changing it to a class)?

[henrika (OOO until Aug 14), 2013/01/16 16:37:17]

No they are not (accessed outside content that is).

You mean that I should change the MediasStreamDevice to a class (and add a
subclass with only two members); right? Not sure how that would allow me to use
media::ChannelLayout. Also, what happens to the IPC part then
(https://codereview.chromium.org/11783059/diff/11017/content/common/media/medi...).
Still possible to send over IPC?

[Jói, 2013/01/16 17:12:01]

The IPC definitions are inside content (i.e. not in content/public) so I would
think they can reference the subclass?

If that doesn't work then I guess it's OK this way, but it is unfortunate to
expose stuff in content/public that isn't meant for consumption outside of
content.

+
+  // Preferred channel configuration for the device.
+  // Only utilized for audio devices.
+  // TODO(henrika): ideally, we would like to use media::ChannelLayout here
+  // but including media/base/channel_layout.h violates checkdeps rules.
+  int channel_layout;
 };
 
 typedef std::vector<MediaStreamDevice> MediaStreamDevices;