Fixed cross compilation with mingw.

src/ports/SkOSFile_win.cpp

Index: src/ports/SkOSFile_win.cpp
diff --git a/src/ports/SkOSFile_win.cpp b/src/ports/SkOSFile_win.cpp
index 7fec557987e307d6faae0789aea88a04f51fc294..fd1c367318cb75dca70f6404dffabadb532c7f3f 100644
--- a/src/ports/SkOSFile_win.cpp
+++ b/src/ports/SkOSFile_win.cpp
@@ -50,18 +50,18 @@ bool sk_fidentical(SkFILE* a, SkFILE* b) {
            && aID.fVolume == bID.fVolume;
 }
 
-template <typename HandleType, HandleType InvalidValue, BOOL (WINAPI * Close)(HandleType)>
+template <typename HandleType, LONG_PTR InvalidValue, BOOL (WINAPI * Close)(HandleType)>

[bungeman-skia, 2014/03/14 14:50:37]

Ick, ack, uck. So technically... in the C++ specification 14.3.2 it appears that
it used to be the case that pointer template arguments had to be addresses of
real objects. C++11 extended this to include NULL. The rationale for this is
that some systems don't have flat pointers into which random stuff like -1 can
be stuffed (in fact it seemed like there was some debate about NULL for this
reason as well). VC++ lets this slide, but it is against the spec to have a

template <void* P> struct A { };
typedef A<-1> a;  //  -1 doesn't isn't the address of an object.

I'll have to think about this a bit.

 class SkAutoTHandle : SkNoncopyable {
 public:
     SkAutoTHandle(HandleType handle) : fHandle(handle) { }
     ~SkAutoTHandle() { Close(fHandle); }
     operator HandleType() { return fHandle; }
-    bool isValid() { return InvalidValue != fHandle; }
+    bool isValid() { return HandleType(InvalidValue) != fHandle; }
 private:
     HandleType fHandle;
 };
-typedef SkAutoTHandle<HANDLE, INVALID_HANDLE_VALUE, CloseHandle> SkAutoWinFile;
-typedef SkAutoTHandle<HANDLE, NULL, CloseHandle> SkAutoWinMMap;
+typedef SkAutoTHandle<HANDLE, -1 /* INVALID_HANDLE_VALUE */, CloseHandle> SkAutoWinFile;
+typedef SkAutoTHandle<HANDLE, 0 /* NULL */, CloseHandle> SkAutoWinMMap;
 
 void sk_fmunmap(const void* addr, size_t) {
     UnmapViewOfFile(addr);