Improvements/additions to SkImageCache/SkLazyPixelRef.

src/lazy/SkPurgeableMemoryBlock_common.cpp

Index: src/lazy/SkPurgeableMemoryBlock_common.cpp
diff --git a/src/lazy/SkPurgeableMemoryBlock_common.cpp b/src/lazy/SkPurgeableMemoryBlock_common.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..2fb71ff62107ea62d6a07115032ce59461ae3d78
--- /dev/null
+++ b/src/lazy/SkPurgeableMemoryBlock_common.cpp
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkPurgeableMemoryBlock.h"
+
+SkPurgeableMemoryBlock* SkPurgeableMemoryBlock::CreatePurgeableMemoryBlock(size_t size) {
+    SkASSERT(PlatformSupportsPurgeableMemory());
+    if (!PlatformSupportsPurgeableMemory()) {
+        return NULL;
+    }
+    SkPurgeableMemoryBlock* block = SkNEW_ARGS(SkPurgeableMemoryBlock, (size));
+    if (block->fPinned) {
+        return block;
+    }
+
+    SkDELETE(block);
+    return NULL;
+}
+