Fix warnings.



git-svn-id: http://skia.googlecode.com/svn/trunk@1209 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/GrGpuGLShaders.cpp b/gpu/src/GrGpuGLShaders.cpp
index ff9f3a4..8ffadeb 100644
--- a/gpu/src/GrGpuGLShaders.cpp
+++ b/gpu/src/GrGpuGLShaders.cpp
@@ -509,6 +509,7 @@
     } else
 #endif
     {
+        if (requiresAttributeColors) {} // suppress unused var warning
         desc.fColorType = GrGLProgram::ProgramDesc::kAttribute_ColorType;
     }