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.cpp b/libs/hwui/OpenGLRenderer.cpp
index 6f751e8..f6a21d4 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -1185,6 +1185,12 @@
     return false;
 }
 
+void OpenGLRenderer::outputDisplayList(DisplayList* displayList, uint32_t level) {
+    if (displayList) {
+        displayList->output(*this, level);
+    }
+}
+
 void OpenGLRenderer::drawAlphaBitmap(Texture* texture, float left, float top, SkPaint* paint) {
     int alpha;
     SkXfermode::Mode mode;