Add SkCachedData and use it for SkMipMap

src/core/SkResourceCache.cpp

Index: src/core/SkResourceCache.cpp
diff --git a/src/core/SkResourceCache.cpp b/src/core/SkResourceCache.cpp
index 3098a9a2a13cf678f21cd2144d07e5575fe4483b..a673ec2d51aa4c39aa847c858f8d74fb63867e36 100644
--- a/src/core/SkResourceCache.cpp
+++ b/src/core/SkResourceCache.cpp
@@ -5,6 +5,7 @@
  * found in the LICENSE file.
  */
 
+#include "SkCachedData.h"
 #include "SkChecksum.h"
 #include "SkResourceCache.h"
 #include "SkMipMap.h"
@@ -263,6 +264,15 @@ size_t SkResourceCache::setTotalByteLimit(size_t newLimit) {
     return prevLimit;
 }
 
+SkCachedData* SkResourceCache::newCachedData(size_t bytes) {
+    if (fDiscardableFactory) {
+        SkDiscardableMemory* dm = fDiscardableFactory(bytes);
+        return dm ? SkNEW_ARGS(SkCachedData, (bytes, dm)) : NULL;
+    } else {
+        return SkNEW_ARGS(SkCachedData, (sk_malloc_throw(bytes), bytes));
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkResourceCache::detach(Rec* rec) {
@@ -442,6 +452,11 @@ SkBitmap::Allocator* SkResourceCache::GetAllocator() {
     return get_cache()->allocator();
 }
 
+SkCachedData* SkResourceCache::NewCachedData(size_t bytes) {
+    SkAutoMutexAcquire am(gMutex);
+    return get_cache()->newCachedData(bytes);
+}
+
 void SkResourceCache::Dump() {
     SkAutoMutexAcquire am(gMutex);
     get_cache()->dump();