From f82e98ade385f1cd60b6da9b22c0592301af1cc8 Mon Sep 17 00:00:00 2001
From: Chris Lord <chrislord.net@gmail.com>
Date: Fri, 11 Apr 2014 13:23:09 +0100
Subject: [PATCH] Bug 993475 - Support masks on color layers in
 BasicCompositor. r=mattwoodrow

---
 gfx/layers/basic/BasicCompositor.cpp | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/gfx/layers/basic/BasicCompositor.cpp b/gfx/layers/basic/BasicCompositor.cpp
index e9acebdc32c1..a4c86184c71d 100644
--- a/gfx/layers/basic/BasicCompositor.cpp
+++ b/gfx/layers/basic/BasicCompositor.cpp
@@ -318,9 +318,19 @@ BasicCompositor::DrawQuad(const gfx::Rect& aRect,
       EffectSolidColor* effectSolidColor =
         static_cast<EffectSolidColor*>(aEffectChain.mPrimaryEffect.get());
 
-      dest->FillRect(aRect,
-                     ColorPattern(effectSolidColor->mColor),
-                     DrawOptions(aOpacity));
+      if (sourceMask) {
+        dest->PushClipRect(aRect);
+        Matrix dtTransform = dest->GetTransform();
+        dest->SetTransform(maskTransform);
+        dest->MaskSurface(ColorPattern(effectSolidColor->mColor),
+                          sourceMask, Point(), DrawOptions(aOpacity));
+        dest->SetTransform(dtTransform);
+        dest->PopClip();
+      } else {
+        dest->FillRect(aRect,
+                       ColorPattern(effectSolidColor->mColor),
+                       DrawOptions(aOpacity));
+      }
       break;
     }
     case EFFECT_RGB: {