Allow debugger to be compiled without Ganesh

https://codereview.appspot.com/7311084/



git-svn-id: http://skia.googlecode.com/svn/trunk@7710 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/debugger/QT/SkRasterWidget.h b/debugger/QT/SkRasterWidget.h
index a0355c1..769aa51 100644
--- a/debugger/QT/SkRasterWidget.h
+++ b/debugger/QT/SkRasterWidget.h
@@ -9,7 +9,10 @@
 #ifndef SKRASTERWIDGET_H_
 #define SKRASTERWIDGET_H_
 
+#if SK_SUPPORT_GPU
 #include "SkGpuDevice.h"
+#endif
+
 #include "SkDevice.h"
 #include "SkDebugger.h"