Implement the DDMS heap walking (for native and managed heaps).

This gets you the DDMS histograms of what's on your heaps.

Change-Id: I7133d044030b10a787277faf3a77e20c565e69c5
diff --git a/src/debugger.h b/src/debugger.h
index 85cc1f8..b85a65d 100644
--- a/src/debugger.h
+++ b/src/debugger.h
@@ -258,7 +258,7 @@
   static bool DdmHandleHpsgNhsgChunk(HpsgWhen when, HpsgWhat what, bool native);
 
   static void DdmSendHeapInfo(HpifWhen reason);
-  static void DdmSendHeapSegments(bool shouldLock, bool native);
+  static void DdmSendHeapSegments(bool native);
 };
 
 #define CHUNK_TYPE(_name) \