Enable chromecast gpu perf

The new #ifndef account for what the chromecast sdk
cannot handle (e.g. posix).

Bug: skia:6581
Change-Id: I3d64d25980d80185f8b95c05badee5f665d97cd3
Reviewed-on: https://skia-review.googlesource.com/13811
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/tools/gpu/GrContextFactory.cpp b/tools/gpu/GrContextFactory.cpp
index 5aa5785..0238898 100644
--- a/tools/gpu/GrContextFactory.cpp
+++ b/tools/gpu/GrContextFactory.cpp
@@ -162,9 +162,11 @@
                                                  glShareContext).release();
                     break;
 #endif
+#ifndef SK_NO_COMMAND_BUFFER
                 case kCommandBuffer_ContextType:
                     glCtx = CommandBufferGLTestContext::Create(glShareContext);
                     break;
+#endif
 #if SK_MESA
                 case kMESA_ContextType:
                     glCtx = CreateMesaGLTestContext(glShareContext);