Merge "GLFunctorDrawable: skip alpha filtering" into tm-dev am: ec839b2eb8

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17697994

Change-Id: Ib3954e059ec5ca720df49962c5fb13d30fe00707
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

libs/hwui/pipeline/skia/GLFunctorDrawable.cpp

@@ -61,6 +61,17 @@ void GLFunctorDrawable::onDraw(SkCanvas* canvas) {
         return;
     }
 
+    // canvas may be an AlphaFilterCanvas, which is intended to draw with a
+    // modified alpha. We do not have a way to do this without drawing into an
+    // extra layer, which would have a performance cost. Draw directly into the
+    // underlying gpu canvas. This matches prior behavior and the behavior in
+    // Vulkan.
+    {
+        auto* gpuCanvas = SkAndroidFrameworkUtils::getBaseWrappedCanvas(canvas);
+        LOG_ALWAYS_FATAL_IF(!gpuCanvas, "GLFunctorDrawable::onDraw is using an invalid canvas!");
+        canvas = gpuCanvas;
+    }
+
     // flush will create a GrRenderTarget if not already present.
     canvas->flush();