Fix compile failure on Win64 introduced in r12291.

src/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 444 matching lines @@
         static_cast<int>(100 - (SizeOfObjects() * 100.0) / CommittedMemory()));
 
     isolate_->counters()->heap_fraction_map_space()->AddSample(
         static_cast<int>(
             (map_space()->CommittedMemory() * 100.0) / CommittedMemory()));
     isolate_->counters()->heap_fraction_cell_space()->AddSample(
         static_cast<int>(
             (cell_space()->CommittedMemory() * 100.0) / CommittedMemory()));
 
     isolate_->counters()->heap_sample_total_committed()->AddSample(
-        CommittedMemory() / KB);
+        static_cast<int>(CommittedMemory() / KB));
     isolate_->counters()->heap_sample_total_used()->AddSample(
-        SizeOfObjects() / KB);
+        static_cast<int>(SizeOfObjects() / KB));
     isolate_->counters()->heap_sample_map_space_committed()->AddSample(
-        map_space()->CommittedMemory() / KB);
+        static_cast<int>(map_space()->CommittedMemory() / KB));
     isolate_->counters()->heap_sample_cell_space_committed()->AddSample(
-        cell_space()->CommittedMemory() / KB);
+        static_cast<int>(cell_space()->CommittedMemory() / KB));
   }
 
 #define UPDATE_COUNTERS_FOR_SPACE(space)                                       \
   isolate_->counters()->space##_bytes_available()->Set(                        \
       static_cast<int>(space()->Available()));                                 \
   isolate_->counters()->space##_bytes_committed()->Set(                        \
       static_cast<int>(space()->CommittedMemory()));                           \
   isolate_->counters()->space##_bytes_used()->Set(                             \
       static_cast<int>(space()->SizeOfObjects()));
 #define UPDATE_FRAGMENTATION_FOR_SPACE(space)                                  \
@@ skipping 6781 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   memcpy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   memcpy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal