libhwcomposer: Log and dump app layers of screen frames

Log a frame-by-frame succession of HWComposer layers' data and write
their buffers, if any, into raw or png files based on system property
values.

Change-Id: Icceccf5fff5ab4d78dbc6c28c11210b8837ddfd9
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index 9da10f4..8c51b38 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -59,6 +59,7 @@
 class IVideoOverlay;
 class MDPComp;
 class CopyBit;
+class HwcDebug;
 
 
 struct MDPInfo {
@@ -259,6 +260,7 @@
     qhwc::ListStats listStats[MAX_DISPLAYS];
     qhwc::LayerProp *layerProp[MAX_DISPLAYS];
     qhwc::MDPComp *mMDPComp[MAX_DISPLAYS];
+    qhwc::HwcDebug *mHwcDebug[MAX_DISPLAYS];
 
     //Securing in progress indicator
     bool mSecuring;