extract some common code from PictureRenderer

src/utils/SkDataUtils.cpp

Index: src/utils/SkDataUtils.cpp
diff --git a/src/utils/SkDataUtils.cpp b/src/utils/SkDataUtils.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c5544f71ba3e5a8dc9d74ae0a8b2670564455d32
--- /dev/null
+++ b/src/utils/SkDataUtils.cpp
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkData.h"
+#include "SkDataUtils.h"
+#include "SkStream.h"
+
+/*static*/ SkData* SkDataUtils::ReadIntoSkData(SkStream &stream, size_t maxBytes) {
+    if (0 == maxBytes) {
+        return SkData::NewEmpty();
+    }
+    char* bufStart = reinterpret_cast<char *>(sk_malloc_throw(maxBytes));
+    char* bufPtr = bufStart;
+    size_t bytesRemaining = maxBytes;
+    while (bytesRemaining > 0) {
+        size_t bytesReadThisTime = stream.read(bufPtr, bytesRemaining);
+        if (0 == bytesReadThisTime) {
+            break;
+        }
+        bytesRemaining -= bytesReadThisTime;
+        bufPtr += bytesReadThisTime;
+    }
+    return SkData::NewFromMalloc(bufStart, maxBytes - bytesRemaining);
+}