Code change to avoid signed/unsigned mismatch warnings

fpdfsdk/fpdfview.cpp

Index: fpdfsdk/fpdfview.cpp
diff --git a/fpdfsdk/fpdfview.cpp b/fpdfsdk/fpdfview.cpp
index 1406939e5d72b098aef19ace06cdd2d9e745fe93..86ec2e5ad0fa20dc1c5fb52b04d010a29518e260 100644
--- a/fpdfsdk/fpdfview.cpp
+++ b/fpdfsdk/fpdfview.cpp
@@ -194,7 +194,8 @@ FX_BOOL CPDF_CustomAccess::ReadBlock(void* buffer,
   FX_SAFE_FILESIZE newPos =
       pdfium::base::checked_cast<FX_FILESIZE, size_t>(size);
   newPos += offset;
-  if (!newPos.IsValid() || newPos.ValueOrDie() > m_FileAccess.m_FileLen) {
+  if (!newPos.IsValid() ||
+      newPos.ValueOrDie() > static_cast<FX_FILESIZE>(m_FileAccess.m_FileLen)) {

[Tom Sepez, 2016/03/29 20:29:01]

m_FileLen probably should remaing a FX_FILESIZE until we tackle that issue.

[Wei Li, 2016/03/29 22:21:00]

You meant changing m_FileLen's type to FX_FILESIZE? That was my earlier attempt
too. Unfortunately, FPDF_FILEACCESS is defined in /public, and is already used
outside of pdfium. 

     return FALSE;
   }
   return m_FileAccess.m_GetBlock(m_FileAccess.m_Param, offset, (uint8_t*)buffer,