Reverting bench tests to pre-3546 (i.e., readding "Debug" option) with a SK_DEBUG guard



git-svn-id: http://skia.googlecode.com/svn/trunk@3550 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/benchmain.cpp b/bench/benchmain.cpp
index 4aa2a9e..4f6827d 100644
--- a/bench/benchmain.cpp
+++ b/bench/benchmain.cpp
@@ -281,6 +281,9 @@
 #if SK_ANGLE
     { SkBitmap::kARGB_8888_Config,  "ANGLE",    kGPU_Backend, &gANGLEGLHelper },
 #endif
+#ifdef SK_DEBUG
+    { SkBitmap::kARGB_8888_Config,  "Debug",    kGPU_Backend, &gDebugGLHelper },
+#endif
     { SkBitmap::kARGB_8888_Config,  "NULLGPU",  kGPU_Backend, &gNullGLHelper },
 };