Fix for 2 parallel gpu rendering issues (bigbitmaprect & image-surface)

https://codereview.appspot.com/6816079/



git-svn-id: http://skia.googlecode.com/svn/trunk@6266 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 4a4259e..fd30c54 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -616,7 +616,7 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 void SkGpuDevice::clear(SkColor color) {
-    fContext->clear(NULL, color, fRenderTarget);
+    fContext->clear(NULL, SkColor2GrColor(color), fRenderTarget);
     fNeedClear = false;
 }