hwc: Use layer dirty rect to calculate frame's updating ROI

Use layer dirty rect instead of display frame to calculate frame's ROI.

Change-Id: If5fe93da7815efdf9b44ed683a4d80b397921cf1
diff --git a/libhwcomposer/hwc_mdpcomp.h b/libhwcomposer/hwc_mdpcomp.h
index beb858b..8186fff 100644
--- a/libhwcomposer/hwc_mdpcomp.h
+++ b/libhwcomposer/hwc_mdpcomp.h
@@ -213,6 +213,7 @@
     bool isSupportedForMDPComp(hwc_context_t *ctx, hwc_layer_1_t* layer);
     bool resourceCheck();
     hwc_rect_t getUpdatingFBRect(hwc_display_contents_1_t* list);
+    bool canDoPartialUpdate(hwc_context_t *ctx, hwc_display_contents_1_t* list);
 
     int mDpy;
     static bool sEnabled;