Fix no-gpu debugger.

Review URL: https://codereview.chromium.org/1262723005
diff --git a/debugger/QT/SkCanvasWidget.cpp b/debugger/QT/SkCanvasWidget.cpp
index 9d691cd..49b1526 100644
--- a/debugger/QT/SkCanvasWidget.cpp
+++ b/debugger/QT/SkCanvasWidget.cpp
@@ -42,7 +42,9 @@
     setWidgetVisibility(kGPU_WidgetType, true);
 #endif
     connect(&fRasterWidget, SIGNAL(drawComplete()), this->parentWidget(), SLOT(drawComplete()));
+#if SK_SUPPORT_GPU
     connect(&fGLWidget, SIGNAL(drawComplete()), this->parentWidget(), SLOT(drawComplete()));
+#endif
 }
 
 SkCanvasWidget::~SkCanvasWidget() {}