Plumb HDR capabilities up to SurfaceComposerClient

Plumbs HDR capabilities up from HWC2 through SurfaceFlinger and
ISurfaceComposer to SurfaceComposerClient.

Bug: 25684127
Change-Id: I0f07043ff42bfc7a159f785fee3e84936dc3c280
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 04b5446..418892a 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -722,6 +722,12 @@
     return ComposerService::getComposerService()->getAnimationFrameStats(outStats);
 }
 
+status_t SurfaceComposerClient::getHdrCapabilities(const sp<IBinder>& display,
+        HdrCapabilities* outCapabilities) {
+    return ComposerService::getComposerService()->getHdrCapabilities(display,
+            outCapabilities);
+}
+
 // ----------------------------------------------------------------------------
 
 status_t ScreenshotClient::capture(