Refactor pin/unpinImages to work across pipelines.

Test: existing CTS tests still pass
Change-Id: Ib2607e9853396bad42f298829b5c5da0d210af32
diff --git a/libs/hwui/renderthread/DrawFrameTask.cpp b/libs/hwui/renderthread/DrawFrameTask.cpp
index e3b6dc6..4ff54a5 100644
--- a/libs/hwui/renderthread/DrawFrameTask.cpp
+++ b/libs/hwui/renderthread/DrawFrameTask.cpp
@@ -119,7 +119,7 @@
     int64_t vsync = mFrameInfo[static_cast<int>(FrameInfoIndex::Vsync)];
     mRenderThread->timeLord().vsyncReceived(vsync);
     bool canDraw = mContext->makeCurrent();
-    Caches::getInstance().textureCache.resetMarkInUse(mContext);
+    mContext->unpinImages();
 
     for (size_t i = 0; i < mLayers.size(); i++) {
         mLayers[i]->apply();