Add cast to support 64 bit.

http://code.google.com/p/skia/issues/detail?id=524
Review URL: https://codereview.appspot.com/6038053

git-svn-id: http://skia.googlecode.com/svn/trunk@3701 2bbb7eff-a529-9590-31e7-b0007b416f81

include/core/SkFontHost.h

@@ -17,7 +17,7 @@ class SkDescriptor;
 class SkStream;
 class SkWStream;
 
-typedef uintptr_t SkFontTableTag;
+typedef uint32_t SkFontTableTag;
 
 /** \class SkFontHost
 

src/ports/SkFontHost_mac_coretext.cpp

@@ -1952,7 +1952,9 @@ int SkFontHost::GetTableTags(SkFontID fontID, SkFontTableTag tags[]) {
     int count = CFArrayGetCount(cfArray);
     if (tags) {
         for (int i = 0; i < count; ++i) {
-            tags[i] = (SkFontTableTag)CFArrayGetValueAtIndex(cfArray, i);
+            uintptr_t fontTag = reinterpret_cast<uintptr_t>(
+                    CFArrayGetValueAtIndex(cfArray, i));
+            tags[i] = static_cast<SkFontTableTag>(fontTag);
         }
     }
     return count;