From 7b6ff12193fda666064f0b56fd24644f6ba045cb Mon Sep 17 00:00:00 2001
From: Ryan VanderMeulen <ryanvm@gmail.com>
Date: Tue, 30 Jul 2013 22:28:46 -0400
Subject: [PATCH] Backed out changeset 6846b610be41 (bug 897409) for suspicion
 of making Win8 mochitest-mc perma-orange.

---
 gfx/layers/CopyableCanvasLayer.cpp | 13 +++++++++----
 gfx/layers/client/CanvasClient.cpp |  2 +-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/gfx/layers/CopyableCanvasLayer.cpp b/gfx/layers/CopyableCanvasLayer.cpp
index 5476ee504303..1154321d0e6f 100644
--- a/gfx/layers/CopyableCanvasLayer.cpp
+++ b/gfx/layers/CopyableCanvasLayer.cpp
@@ -74,6 +74,11 @@ CopyableCanvasLayer::UpdateSurface(gfxASurface* aDestSurface, Layer* aMaskLayer)
   }
 
   if (mGLContext) {
+    if (aDestSurface && aDestSurface->GetType() != gfxASurface::SurfaceTypeImage) {
+      MOZ_ASSERT(false, "Destination surface must be ImageSurface type.");
+      return;
+    }
+
     nsRefPtr<gfxImageSurface> readSurf;
     nsRefPtr<gfxImageSurface> resultSurf;
 
@@ -88,9 +93,9 @@ CopyableCanvasLayer::UpdateSurface(gfxASurface* aDestSurface, Layer* aMaskLayer)
                             ? gfxASurface::ImageFormatRGB24
                             : gfxASurface::ImageFormatARGB32;
 
-    bool needsTempSurface = !aDestSurface ||
-                            !(resultSurf = aDestSurface->GetAsImageSurface());
-    if (needsTempSurface) {
+    if (aDestSurface) {
+      resultSurf = static_cast<gfxImageSurface*>(aDestSurface);
+    } else {
       resultSurf = GetTempSurface(readSize, format);
     }
     MOZ_ASSERT(resultSurf);
@@ -151,7 +156,7 @@ CopyableCanvasLayer::UpdateSurface(gfxASurface* aDestSurface, Layer* aMaskLayer)
     }
 
     // stick our surface into mSurface, so that the Paint() path is the same
-    if (needsTempSurface) {
+    if (!aDestSurface) {
       mSurface = resultSurf;
     }
   }
diff --git a/gfx/layers/client/CanvasClient.cpp b/gfx/layers/client/CanvasClient.cpp
index 8bd9d48dcf80..2286ab87d156 100644
--- a/gfx/layers/client/CanvasClient.cpp
+++ b/gfx/layers/client/CanvasClient.cpp
@@ -66,7 +66,7 @@ CanvasClient2D::Update(gfx::IntSize aSize, ClientCanvasLayer* aLayer)
                                               : gfxASurface::CONTENT_COLOR_ALPHA;
   mDeprecatedTextureClient->EnsureAllocated(aSize, contentType);
 
-  gfxASurface* surface = mDeprecatedTextureClient->LockSurface();
+  gfxASurface* surface = mDeprecatedTextureClient->LockImageSurface();
   aLayer->UpdateSurface(surface);
   mDeprecatedTextureClient->Unlock();
 }