move annotations to canvas virtual

src/core/SkReader32.h

Index: src/core/SkReader32.h
diff --git a/src/core/SkReader32.h b/src/core/SkReader32.h
index 68dda23c6efcbd53fdc4c9758729229970b5a65c..645d64cc24590b5c6fc784b5be6878e0ff7b19fd 100644
--- a/src/core/SkReader32.h
+++ b/src/core/SkReader32.h
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2008 The Android Open Source Project
  *
@@ -10,6 +9,7 @@
 #ifndef SkReader32_DEFINED
 #define SkReader32_DEFINED
 
+#include "SkData.h"
 #include "SkMatrix.h"
 #include "SkPath.h"
 #include "SkRegion.h"
@@ -135,6 +135,14 @@ public:
      */
     size_t readIntoString(SkString* copy);
 
+    SkData* readData() {
+        uint32_t byteLength = this->readU32();
+        if (0 == byteLength) {
+            return SkData::NewEmpty();
+        }
+        return SkData::NewWithCopy(this->skip(byteLength), byteLength);
+    }
+
 private:
     template <typename T> bool readObjectFromMemory(T* obj) {
         size_t size = obj->readFromMemory(this->peek(), this->available());