Adds a build flag for GL to never use vertex attributes that don't have per-vertex values.
Also promotes the ATTRIBUTE_MATRIX flag that was local to cpp files to the public config file.

Review URL: http://codereview.appspot.com/4434057/

git-svn-id: http://skia.googlecode.com/svn/trunk@1155 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/include/GrDrawTarget.h b/gpu/include/GrDrawTarget.h
index 349cafd..038e776 100644
--- a/gpu/include/GrDrawTarget.h
+++ b/gpu/include/GrDrawTarget.h
@@ -498,7 +498,7 @@
         kHighVertexLayoutBit = kDummyVertexLayoutBit - 1
     };
     // make sure we haven't exceeded the number of bits in GrVertexLayout.
-    GR_STATIC_ASSERT(kHighVertexLayoutBit < (1 << 8*sizeof(GrVertexLayout)));
+    GR_STATIC_ASSERT(kHighVertexLayoutBit < ((uint64_t)1 << 8*sizeof(GrVertexLayout)));
 
     /**
      * There are three paths for specifying geometry (vertices and optionally