Rearrange SkRecord with small N in mind

src/core/SkVarAlloc.cpp

Index: src/core/SkVarAlloc.cpp
diff --git a/src/core/SkVarAlloc.cpp b/src/core/SkVarAlloc.cpp
index 88bd17028fbe19156e448e3f066cb2b0230421ca..fa89d38c23a286a03f4d28d92bb1996a428ae607 100644
--- a/src/core/SkVarAlloc.cpp
+++ b/src/core/SkVarAlloc.cpp
@@ -1,3 +1,10 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
 #include "SkVarAlloc.h"
 
 // We use non-standard malloc diagnostic methods to make sure our allocations are sized well.
@@ -25,6 +32,12 @@ SkVarAlloc::SkVarAlloc(size_t minLgSize)
     , fLgSize(minLgSize)
     , fBlock(NULL) {}
 
+SkVarAlloc::SkVarAlloc(size_t minLgSize, char* storage, size_t len)
+    : fByte(storage)
+    , fRemaining(len)
+    , fLgSize(minLgSize)
+    , fBlock(NULL) {}
+
 SkVarAlloc::~SkVarAlloc() {
     Block* b = fBlock;
     while (b) {