Hide fields in SkImageInfo

R=rmistry@google.com
TBR=bsalomon

Author: reed@google.com

Review URL: https://codereview.chromium.org/536003002
diff --git a/tools/LazyDecodeBitmap.cpp b/tools/LazyDecodeBitmap.cpp
index 4459cf1..ec275ea 100644
--- a/tools/LazyDecodeBitmap.cpp
+++ b/tools/LazyDecodeBitmap.cpp
@@ -39,7 +39,7 @@
         return false;
     }
     SkDiscardableMemory::Factory* pool = NULL;
-    if ((!FLAGS_useVolatileCache) || (info.fWidth * info.fHeight < 32 * 1024)) {
+    if ((!FLAGS_useVolatileCache) || (info.width() * info.height() < 32 * 1024)) {
         // how to do switching with SkDiscardableMemory.
         pool = SkGetGlobalDiscardableMemoryPool();
         // Only meaningful if platform has a default discardable