Use audio_format_t consistently, continued

Was int or uint32_t.

When AudioFlinger::format can't determine the correct format,
return INVALID rather than DEFAULT.

Init mFormat to INVALID rather than DEFAULT in the constructor.
Subclass constructors will set mFormat to the correct value.

Change-Id: I9b62640aa107d24d2d27925f5563d0d7407d1b73
diff --git a/services/audioflinger/AudioPolicyService.cpp b/services/audioflinger/AudioPolicyService.cpp
index 7a408bc..28b1c89 100644
--- a/services/audioflinger/AudioPolicyService.cpp
+++ b/services/audioflinger/AudioPolicyService.cpp
@@ -241,7 +241,7 @@
 
 audio_io_handle_t AudioPolicyService::getOutput(audio_stream_type_t stream,
                                     uint32_t samplingRate,
-                                    uint32_t format,
+                                    audio_format_t format,
                                     uint32_t channels,
                                     audio_policy_output_flags_t flags)
 {
@@ -289,7 +289,7 @@
 
 audio_io_handle_t AudioPolicyService::getInput(int inputSource,
                                     uint32_t samplingRate,
-                                    uint32_t format,
+                                    audio_format_t format,
                                     uint32_t channels,
                                     audio_in_acoustics_t acoustics,
                                     int audioSession)
@@ -1352,7 +1352,7 @@
 static audio_io_handle_t aps_open_output(void *service,
                                              uint32_t *pDevices,
                                              uint32_t *pSamplingRate,
-                                             uint32_t *pFormat,
+                                             audio_format_t *pFormat,
                                              uint32_t *pChannels,
                                              uint32_t *pLatencyMs,
                                              audio_policy_output_flags_t flags)
@@ -1413,7 +1413,7 @@
 static audio_io_handle_t aps_open_input(void *service,
                                             uint32_t *pDevices,
                                             uint32_t *pSamplingRate,
-                                            uint32_t *pFormat,
+                                            audio_format_t *pFormat,
                                             uint32_t *pChannels,
                                             uint32_t acoustics)
 {