Change DebugCanvas API to not encourage memory leaks

debugger/QT/SkDebuggerGUI.h

Index: debugger/QT/SkDebuggerGUI.h
diff --git a/debugger/QT/SkDebuggerGUI.h b/debugger/QT/SkDebuggerGUI.h
index 3f445500c7801a7c8e18c94080d3d0ce5c644801..2a514baef1bc9836ad8b63bb05f50cd8d6c4720d 100644
--- a/debugger/QT/SkDebuggerGUI.h
+++ b/debugger/QT/SkDebuggerGUI.h
@@ -334,14 +334,14 @@ private:
     void saveToFile(const SkString& filename);
 
     /**
-        Populates the list widget with the vector of strings passed in.
+        Populates the list widget with the debugger draw command info.
      */
-    void setupListWidget(SkTArray<SkString>* commands, SkTDArray<size_t>* offsets);
+    void setupListWidget();
 
     /**
-        Populates the combo box widget with the vector of strings passed in.
+        Populates the combo box widget with with the debugger draw command info.
      */
-    void setupComboBox(SkTArray<SkString>* command);
+    void setupComboBox();
 
     /**
         Fills in the overview pane with text