debugger: Update the picture view when the first command is selected

debugger/SkDebugger.h

Index: debugger/SkDebugger.h
diff --git a/debugger/SkDebugger.h b/debugger/SkDebugger.h
index 683b98d6d949eae6f859676b27aeaf560c32166c..5906acc43ee5137831174c9b2cf6a8b856f69978 100644
--- a/debugger/SkDebugger.h
+++ b/debugger/SkDebugger.h
@@ -26,7 +26,7 @@ public:
         fIndex = index;
     }
     void draw(SkCanvas* canvas) {
-        if (fIndex > 0) {
+        if (fIndex >= 0) {
             fDebugCanvas->drawTo(canvas, fIndex);
         }
     }