cc: Reject non-opaque fullscreen overlay candidates.

cc/output/overlay_strategy_fullscreen.cc

Index: cc/output/overlay_strategy_fullscreen.cc
diff --git a/cc/output/overlay_strategy_fullscreen.cc b/cc/output/overlay_strategy_fullscreen.cc
index 681611fa5f233f99094eb6656d8d12d8be93cfd8..7082441cf46cddd90dc433db66e6d30146b2a544 100644
--- a/cc/output/overlay_strategy_fullscreen.cc
+++ b/cc/output/overlay_strategy_fullscreen.cc
@@ -38,8 +38,14 @@ bool OverlayStrategyFullscreen::Attempt(
   if (front == quad_list->end())
     return false;
 
+  const DrawQuad* quad = *front;
+  if (quad->ShouldDrawWithBlending() ||
+      quad->shared_quad_state->opacity != 1.f ||
+      quad->shared_quad_state->blend_mode != SkBlendMode::kSrcOver)
+    return false;
+
   OverlayCandidate candidate;
-  if (!OverlayCandidate::FromDrawQuad(resource_provider, *front, &candidate)) {
+  if (!OverlayCandidate::FromDrawQuad(resource_provider, quad, &candidate)) {
     return false;
   }