get rid off preserve backbuffer optimization in SF

this optimization didn't improve performance and in fact
seemed to hurt more than anything else. it also made
things a lot more complex as it introduced edges cases
when switching to/from h/w composer.

Change-Id: Iaafc235e175f5740cd98bff914d706e02ab88bb8

1 files changed, 1 insertions, 9 deletions

diff --git a/services/surfaceflinger/LayerBase.cpp b/services/surfaceflinger/LayerBase.cpp
index e764001206..416fc93e17 100644
--- a/services/surfaceflinger/LayerBase.cpp
+++ b/services/surfaceflinger/LayerBase.cpp
@@ -43,7 +43,7 @@ LayerBase::LayerBase(SurfaceFlinger* flinger, DisplayID display)
     : dpy(display), contentDirty(false),
       sequence(uint32_t(android_atomic_inc(&sSequence))),
       mFlinger(flinger), mFiltering(false),
-      mNeedsFiltering(false), mInOverlay(false),
+      mNeedsFiltering(false),
       mOrientation(0),
       mPlaneOrientation(0),
       mTransactionFlags(0),
@@ -333,14 +333,6 @@ void LayerBase::setPerFrameData(hwc_layer_t* hwcl) {
     hwcl->handle = NULL;
 }
 
-void LayerBase::setOverlay(bool inOverlay) {
-    mInOverlay = inOverlay;
-}
-
-bool LayerBase::isOverlay() const {
-    return mInOverlay;
-}
-
 void LayerBase::setFiltering(bool filtering)
 {
     mFiltering = filtering;