Updated blur to use A8/R8 (instead of RGBA8) when available - this provides a performance gain for large blurs

http://codereview.appspot.com/5988071/



git-svn-id: http://skia.googlecode.com/svn/trunk@3647 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index aeb104c..57e73c4 100644
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -57,6 +57,10 @@
     poolState.fPoolStartIndex = DEBUG_INVAL_START_IDX;
 #endif
     resetStats();
+
+    for (int i = 0; i < kGrPixelConfigCount; ++i) {
+        fConfigRenderSupport[i] = false;
+    };
 }
 
 GrGpu::~GrGpu() {