some fixes and warning disables in ui/ for building on win x64

ui/gfx/icon_util.cc

Index: ui/gfx/icon_util.cc
diff --git a/ui/gfx/icon_util.cc b/ui/gfx/icon_util.cc
index 4f4b4b7c68f576b10d499f67c43a9dc466c56bd7..bff7c88034f2914f166447d5a6f67e57b940f2d0 100644
--- a/ui/gfx/icon_util.cc
+++ b/ui/gfx/icon_util.cc
@@ -331,7 +331,7 @@ bool IconUtil::CreateIconFileFromSkBitmap(const SkBitmap& bitmap,
   std::vector<uint8> buffer(buffer_size);
   ICONDIR* icon_dir = reinterpret_cast<ICONDIR*>(&buffer[0]);
   icon_dir->idType = kResourceTypeIcon;
-  icon_dir->idCount = bitmap_count;
+  icon_dir->idCount = static_cast<WORD>(bitmap_count);
   size_t icon_dir_count = bitmap_count - 1;  // Note DCHECK(!bitmaps.empty())!
 
   // Increment counts if a PNG entry will be added.
@@ -358,8 +358,8 @@ bool IconUtil::CreateIconFileFromSkBitmap(const SkBitmap& bitmap,
     entry->bHeight = 0;
     entry->wPlanes = 1;
     entry->wBitCount = 32;
-    entry->dwBytesInRes = png_bytes->size();
-    entry->dwImageOffset = offset;
+    entry->dwBytesInRes = static_cast<DWORD>(png_bytes->size());

[jschuh, 2013/01/14 21:31:39]

It doesn't look like we validate the size anywhere in here to prevent overflow.
Is it done elsewhere?

[scottmg, 2013/01/14 21:45:00]

No.

I was trying to imagine where a case where it would matter, but I couldn't think
of any... is a CHECK reasonable here?

[jschuh, 2013/01/14 22:14:35]

Sounds good to me. You can convert the DCHECKs on 300 and 301. 

+    entry->dwImageOffset = static_cast<DWORD>(offset);
     memcpy(&buffer[offset], png_bytes->front(), png_bytes->size());
     offset += png_bytes->size();
   }