Fix GLPrograms unit test, only set fExperimentalGS if driver support is 
available



git-svn-id: http://skia.googlecode.com/svn/trunk@2367 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/GrGpuGLShaders.cpp b/gpu/src/GrGpuGLShaders.cpp
index 4f39965..ea528f8 100644
--- a/gpu/src/GrGpuGLShaders.cpp
+++ b/gpu/src/GrGpuGLShaders.cpp
@@ -220,7 +220,8 @@
         pdesc.fFirstCoverageStage = idx;
 
 #if GR_GL_EXPERIMENTAL_GS
-        pdesc.fExperimentalGS = random.nextF() > .5f;
+        pdesc.fExperimentalGS = this->getCaps().fGeometryShaderSupport &&
+                                random.nextF() > .5f;
 #endif
 
         bool edgeAA = random.nextF() > .5f;