[tracing] Add support for skia caches to dump memory stats

src/core/SkResourceCache.h

Index: src/core/SkResourceCache.h
diff --git a/src/core/SkResourceCache.h b/src/core/SkResourceCache.h
index 7267c6739b5f7edb65332d7d0e62ab11a4538fed..8fb2c86d0298ad45d1955c61b6b8aede50cb2be0 100644
--- a/src/core/SkResourceCache.h
+++ b/src/core/SkResourceCache.h
@@ -14,6 +14,7 @@
 
 class SkCachedData;
 class SkDiscardableMemory;
+class SkTraceMemoryDump;
 
 /**
  *  Cache object for bitmaps (with possible scale in X Y as part of the key).
@@ -152,6 +153,11 @@ public:
 
     static void TestDumpMemoryStatistics();
 
+    /** Dump memory usage statistics of every Rec in the cache using the
+        SkTraceMemoryDump interface.
+     */
+    static void DumpMemoryStatistics(SkTraceMemoryDump* dump);
+
     /**
      *  Returns the DiscardableFactory used by the global cache, or NULL.
      */