First pass at Comment API

include/utils/SkDumpCanvas.h

Index: include/utils/SkDumpCanvas.h
===================================================================
--- include/utils/SkDumpCanvas.h	(revision 8806)
+++ include/utils/SkDumpCanvas.h	(working copy)
@@ -45,7 +45,11 @@
         kDrawText_Verb,
         kDrawPicture_Verb,
         kDrawVertices_Verb,
-        kDrawData_Verb
+        kDrawData_Verb,
+
+        kBeginGroup_Verb,
+        kAddComment_Verb,
+        kEndGroup_Verb
     };
 
     /** Subclasses of this are installed on the DumpCanvas, and then called for
@@ -117,6 +121,9 @@
                               const uint16_t indices[], int indexCount,
                               const SkPaint& paint) SK_OVERRIDE;
     virtual void drawData(const void*, size_t) SK_OVERRIDE;
+    virtual void beginGroup(const char* description) SK_OVERRIDE;
+    virtual void addComment(const char* kywd, const char* value) SK_OVERRIDE;
+    virtual void endGroup() SK_OVERRIDE;
 
 private:
     Dumper* fDumper;