Add ability for hierarchyviewer to output displaylist info

Clicking on a node in hierarchyviewer1 and hierarchyviewer2 and then
clicking the new "Dump DisplayList" button will cause the display
list for the selected node (including its children) to be output into
logcat.

Change-Id: Iad05f5f6cca0f8b465dccd962b501dc18fe6e053
diff --git a/libs/hwui/OpenGLRenderer.h b/libs/hwui/OpenGLRenderer.h
index b5c37c2..271e4b1 100644
--- a/libs/hwui/OpenGLRenderer.h
+++ b/libs/hwui/OpenGLRenderer.h
@@ -98,6 +98,7 @@
 
     virtual bool drawDisplayList(DisplayList* displayList, uint32_t width, uint32_t height,
             Rect& dirty, uint32_t level = 0);
+    virtual void outputDisplayList(DisplayList* displayList, uint32_t level = 0);
     virtual void drawLayer(Layer* layer, float x, float y, SkPaint* paint);
     virtual void drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint);
     virtual void drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint);