Implement SkPicture::bytesUsed() for SkRecord backend

src/core/SkQuadTree.cpp

Index: src/core/SkQuadTree.cpp
diff --git a/src/core/SkQuadTree.cpp b/src/core/SkQuadTree.cpp
index 1fc3cd0192a26c64efe3a06ef5baf4cfd8a17aec..ecf38b8b512826d5c4be4a58c1ca8896969f50ab 100644
--- a/src/core/SkQuadTree.cpp
+++ b/src/core/SkQuadTree.cpp
@@ -208,6 +208,14 @@ void SkQuadTree::rewindInserts() {
     }
 }
 
+size_t SkQuadTree::bytesUsed() const {
+    size_t byteCount = sizeof(SkQuadTree);
+    byteCount += fEntryPool.allocated() * sizeof(Entry);
+    byteCount += fNodePool.allocated() * sizeof(Node);
+    byteCount += fDeferred.getCount() * sizeof(Entry);
+    return byteCount;
+}
+
 void SkQuadTree::flushDeferredInserts() {
     if (NULL == fRoot) {
         fRoot = fNodePool.acquire();