Fix more disabled MSVC warnings, base/ edition.

base/debug/crash_logging.cc

Index: base/debug/crash_logging.cc
diff --git a/base/debug/crash_logging.cc b/base/debug/crash_logging.cc
index caf10b49b07185dfcf26eeb9b6fcdbe471f21151..2001a7869223e8d3f85f8eee7907ccf783568294 100644
--- a/base/debug/crash_logging.cc
+++ b/base/debug/crash_logging.cc
@@ -36,7 +36,7 @@ ClearCrashKeyValueFuncT g_clear_key_func_ = NULL;
 // For a given |length|, computes the number of chunks a value of that size
 // will occupy.
 size_t NumChunksForLength(size_t length) {
-  return std::ceil(length / static_cast<float>(g_chunk_max_length_));

[brettw, 2014/10/01 17:54:06]

I felt like the intent of the old code was clearer here, even if it involved an
"ugly" round-trip through floating-point-land. Can we just cast the result (I
assume there's a warning here or you wouldn't be changing it).

[Peter Kasting, 2014/10/01 19:30:21]

We can cast the result, but if something is unclear, I think it would be better
to add a comment than use floating-point math for a case when we don't need it. 
(I'm actually surprised you're not familiar with the (n+k-1)/k idiom, I thought
it was pretty well-known.)

I added a comment, see what you think.

+  return (length + g_chunk_max_length_ - 1) / g_chunk_max_length_;
 }
 
 // The longest max_length allowed by the system.