Fix leak in SkFontHost_fontconfig temporary code.

src/ports/SkFontHost_fontconfig.cpp

Index: src/ports/SkFontHost_fontconfig.cpp
===================================================================
--- src/ports/SkFontHost_fontconfig.cpp	(revision 9450)
+++ src/ports/SkFontHost_fontconfig.cpp	(working copy)
@@ -154,7 +154,9 @@
         SkAutoTMalloc<uint8_t> allocMemory(length);
         stream->rewind();
         if (length == stream->read(allocMemory.get(), length)) {
-            return new SkMemoryStream(allocMemory.detach(), length);
+            SkAutoTUnref<SkMemoryStream> copyStream(new SkMemoryStream());
+            copyStream->setMemoryOwned(allocMemory.detach(), length);
+            return copyStream.detach();
         }
 
         stream->rewind();