Add plumbing for HDR metadata

Allow a ANativeWindow client to send HDR metadata to SurfaceFlinger.
The metadata can be queried with
BufferLayerConsumer::getCurrentHdrMetadata.

Written by Courtney.  Updated by olv@.

Bug: 63710530
Test: builds
Change-Id: I23192d4750950664b57863a533bffd72397255b4
diff --git a/services/surfaceflinger/BufferLayerConsumer.h b/services/surfaceflinger/BufferLayerConsumer.h
index 9b18608..51c2b41 100644
--- a/services/surfaceflinger/BufferLayerConsumer.h
+++ b/services/surfaceflinger/BufferLayerConsumer.h
@@ -21,6 +21,7 @@
 
 #include <gui/BufferQueueDefs.h>
 #include <gui/ConsumerBase.h>
+#include <gui/HdrMetadata.h>
 
 #include <ui/FenceTime.h>
 #include <ui/GraphicBuffer.h>
@@ -121,6 +122,10 @@
     // set by the most recent call to updateTexImage.
     android_dataspace getCurrentDataSpace();
 
+    // getCurrentHdrMetadata retrieves the HDR metadata associated with the
+    // texture image set by the most recent call to updateTexImage.
+    const HdrMetadata& getCurrentHdrMetadata() const;
+
     // getFrameNumber retrieves the frame number associated with the texture
     // image set by the most recent call to updateTexImage.
     //
@@ -316,6 +321,10 @@
     // gets set each time updateTexImage is called.
     android_dataspace mCurrentDataSpace;
 
+    // mCurrentHdrMetadata is the HDR metadata for the current texture. It
+    // gets set each time updateTexImage is called.
+    HdrMetadata mCurrentHdrMetadata;
+
     // mCurrentFrameNumber is the frame counter for the current texture.
     // It gets set each time updateTexImage is called.
     uint64_t mCurrentFrameNumber;