audio policy: volume control reorganization

Output volume and routing control by AudioOutputDescriptor
is reorganized to prepare hardware source volume and routing
control.
AudioOutputDescriptor contains all volume, device and activity
state common to software (audio flinger mixers) and
hardware sources (tuners, A2DP, HDMI).
A new class SwAudioOutputDescriptor is derived from
AudioOutputDescriptor and is specific to software sources.

Low level routing and volume control methods receive an
AudioOutputDescriptor parameter instead of an IO handle.

mPrimaryOutput is now an AudioOutputDescriptor.

Change-Id: Ie90943ee3102cdb8adf89fdd2addd2c279b1e5bf
diff --git a/services/audiopolicy/enginedefault/src/Engine.cpp b/services/audiopolicy/enginedefault/src/Engine.cpp
index 417eebc..26a0d09 100755
--- a/services/audiopolicy/enginedefault/src/Engine.cpp
+++ b/services/audiopolicy/enginedefault/src/Engine.cpp
@@ -243,7 +243,7 @@
 
 routing_strategy Engine::getStrategyForUsage(audio_usage_t usage)
 {
-    const AudioOutputCollection &outputs = mApmObserver->getOutputs();
+    const SwAudioOutputCollection &outputs = mApmObserver->getOutputs();
 
     // usage to strategy mapping
     switch (usage) {
@@ -291,7 +291,7 @@
     const DeviceVector &availableOutputDevices = mApmObserver->getAvailableOutputDevices();
     const DeviceVector &availableInputDevices = mApmObserver->getAvailableInputDevices();
 
-    const AudioOutputCollection &outputs = mApmObserver->getOutputs();
+    const SwAudioOutputCollection &outputs = mApmObserver->getOutputs();
 
     uint32_t device = AUDIO_DEVICE_NONE;
     uint32_t availableOutputDevicesType = availableOutputDevices.types();
@@ -582,7 +582,7 @@
 {
     const DeviceVector &availableOutputDevices = mApmObserver->getAvailableOutputDevices();
     const DeviceVector &availableInputDevices = mApmObserver->getAvailableInputDevices();
-    const AudioOutputCollection &outputs = mApmObserver->getOutputs();
+    const SwAudioOutputCollection &outputs = mApmObserver->getOutputs();
     audio_devices_t availableDeviceTypes = availableInputDevices.types() & ~AUDIO_DEVICE_BIT_IN;
 
     uint32_t device = AUDIO_DEVICE_NONE;