Verify YUVA channel information and add premultiplied alpha

Bug: skia:7903
Change-Id: Ia5394192febd1ffb6f2dcf700fc551407ceb80c1
Reviewed-on: https://skia-review.googlesource.com/c/170265
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
diff --git a/src/gpu/GrImageTextureMaker.cpp b/src/gpu/GrImageTextureMaker.cpp
index d324c5a..567e91e 100644
--- a/src/gpu/GrImageTextureMaker.cpp
+++ b/src/gpu/GrImageTextureMaker.cpp
@@ -90,6 +90,9 @@
     const GrSamplerState::Filter* filterOrNullForBicubic) {
 
     // Check simple cases to see if we need to fall back to flattening the image
+    // TODO: See if we can relax this -- for example, if filterConstraint
+    //       is kYes_FilterConstraint we still may not need a TextureDomain
+    //       in some cases.
     if (!textureMatrix.isIdentity() || kNo_FilterConstraint != filterConstraint ||
         !coordsLimitedToConstraintRect || !filterOrNullForBicubic) {
         return this->INHERITED::createFragmentProcessor(textureMatrix, constraintRect,