SurfaceFlinger: Change to support client target flip

- Add support to flip framebuffer target if
  HWC2 implementation requests for it.

b/38114488
b/68271386
CRs-Fixed: 2057401
Change-Id: I91422ef60a139cbaf491db219b216cd1252e7e63
Signed-off-by: Madhuri Athota <mathota@codeaurora.org>
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 74b3a38..c9e530d 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -108,6 +108,9 @@
     // does this display have layers handled by HWC
     bool hasDeviceComposition(int32_t displayId) const;
 
+    // does this display have pending request to flip client target
+    bool hasFlipClientTargetRequest(int32_t displayId) const;
+
     // does this display have layers handled by GLES
     bool hasClientComposition(int32_t displayId) const;