remove unused/deprecated flags from savelayer

Test: make

Change-Id: I39e41a80430dca7878e6983b098c1c4541904fd1

libs/hwui/SkiaCanvas.cpp

@@ -187,11 +187,6 @@ void SkiaCanvas::restoreToCount(int restoreCount) {
 static inline SkCanvas::SaveLayerFlags layerFlags(SaveFlags::Flags flags) {
     SkCanvas::SaveLayerFlags layerFlags = 0;
 
-    // We intentionally ignore the SaveFlags::HasAlphaLayer and
-    // SkCanvas::kIsOpaque_SaveLayerFlag flags because HWUI ignores it
-    // and our Android client may use it incorrectly.
-    // In Skia, this flag is purely for performance optimization.
-
     if (!(flags & SaveFlags::ClipToLayer)) {
         layerFlags |= SkCanvas::kDontClipToLayer_Legacy_SaveLayerFlag;
     }

libs/hwui/SkiaCanvasProxy.cpp

@@ -204,10 +204,6 @@ static inline SaveFlags::Flags saveFlags(SkCanvas::SaveLayerFlags layerFlags) {
         saveFlags |= SaveFlags::ClipToLayer;
     }
 
-    if (!(layerFlags & SkCanvas::kIsOpaque_SaveLayerFlag)) {
-        saveFlags |= SaveFlags::HasAlphaLayer;
-    }
-
     return saveFlags;
 }