sys_info_linux: positive return value of MaxSharedMemorySize for 32-bit build on 64-bit host.

base/sys_info_freebsd.cc

Index: base/sys_info_freebsd.cc
diff --git a/base/sys_info_freebsd.cc b/base/sys_info_freebsd.cc
index 832b35985bedb4010a0130c3e6cf554a8ebbb265..515b59d6e9845d8e20f35ce9217dd597fe7b0c97 100644
--- a/base/sys_info_freebsd.cc
+++ b/base/sys_info_freebsd.cc
@@ -23,14 +23,14 @@ int64 SysInfo::AmountOfPhysicalMemory() {
 }
 
 // static
-size_t SysInfo::MaxSharedMemorySize() {
+uint64 SysInfo::MaxSharedMemorySize() {
   size_t limit;
   size_t size = sizeof(limit);
   if (sysctlbyname("kern.ipc.shmmax", &limit, &size, NULL, 0) < 0) {
     NOTREACHED();
     return 0;
   }
-  return limit;
+  return static_cast<uint64>(limit);
 }
 
 }  // namespace base