Enable platform echo cancellation through the AudioRecord path.

Add a platform effects mask member to AudioParameters. This allows the
availability of platform effects (currently AEC) to be plumbed up to
MediaStreamDependencyFactory, where they can be reconciled with the
media constraints to determine if the effects should be enabled. When
this is the case, the constraints will be modified to disable the
corresponding software effect in PeerConnection.

The availability is controlled by a whitelist of device models in
AudioManagerAndroid, which for AEC, currently consists of Nexus 5 and
Nexus 7.

AudioManagerAndroid will use the AudioRecord path iff the platform
AEC is enabled.

TESTED=Using apprtc on a N5 and N7 (whitelisted):
- The AudioRecord input path is used.
- The platform AEC is enabled and the software AEC (in PeerConnection)
is disabled.
- Calls have good echo cancellation quality.

Using apprtc with ?audio=googEchoCancellation=false on a N5 and N7:
- The OpenSLES input path is used.
- Both the platform and software AEC are disabled.

Using apprtc on Nexus 4 (non-whitelisted):
- The OpenSLES input path is used.
- The platform AEC is disabled and the software AEC is enabled.

Using apprtc on Galaxy S2 (running ICS):
- The OpenSLES input path is used.

audio_android_unittest.cc passes on N5, N7 and Galaxy S2

TBR=jschuh

Review URL: https://codereview.chromium.org/99033003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240548 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 7 insertions, 3 deletions

diff --git a/content/public/common/media_stream_request.h b/content/public/common/media_stream_request.h
index e6870e1..a117931 100644
--- a/content/public/common/media_stream_request.h
+++ b/content/public/common/media_stream_request.h
@@ -106,14 +106,15 @@ struct CONTENT_EXPORT MediaStreamDevice {
   // in media::AudioParameters.
   struct AudioDeviceParameters {
     AudioDeviceParameters()
-        : sample_rate(), channel_layout(), frames_per_buffer() {
+        : sample_rate(), channel_layout(), frames_per_buffer(), effects() {
     }
 
     AudioDeviceParameters(int sample_rate, int channel_layout,
-                          int frames_per_buffer)
+        int frames_per_buffer)
         : sample_rate(sample_rate),
           channel_layout(channel_layout),
-          frames_per_buffer(frames_per_buffer) {
+          frames_per_buffer(frames_per_buffer),
+          effects() {
     }
 
     // Preferred sample rate in samples per second for the device.
@@ -129,6 +130,9 @@ struct CONTENT_EXPORT MediaStreamDevice {
     // expected browser side settings and avoid unnecessary buffering.
     // See media::AudioParameters for more.
     int frames_per_buffer;
+
+    // See media::AudioParameters::PlatformEffectsMask.
+    int effects;
   };
 
   // These below two member variables are valid only when the type of device is