Fixed invalid cast on mingw.

src/ports/SkThread_win.cpp

Index: src/ports/SkThread_win.cpp
diff --git a/src/ports/SkThread_win.cpp b/src/ports/SkThread_win.cpp
index bc038b2289e4c6b7d5b272b5fa012cf3d8388449..d51c858f013817f02555a24d4e9f772b263d305d 100644
--- a/src/ports/SkThread_win.cpp
+++ b/src/ports/SkThread_win.cpp
@@ -36,7 +36,7 @@ void sk_membar_aquire__after_atomic_dec() { }
 
 int32_t sk_atomic_conditional_inc(int32_t* addr) {
     while (true) {
-        LONG value = static_cast<LONG const volatile&>(*addr);
+        LONG value = static_cast<LONG const volatile>(*addr);

[caryclark, 2013/06/18 11:57:55]

is the const still required?

         if (value == 0) {
             return 0;
         }