Fix more disabled MSVC warnings, base/ edition.

base/debug/crash_logging.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/debug/crash_logging.h"
 
 #include <cmath>
 #include <map>
 
 #include "base/debug/stack_trace.h"
@@ skipping 18 matching lines @@
 const char kChunkFormatString[] = "%s-%" PRIuS;
 
 // The functions that are called to actually set the key-value pairs in the
 // crash reportng system.
 SetCrashKeyValueFuncT g_set_key_func_ = NULL;
 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.
 const size_t kLargestValueAllowed = 1024;
 
 }  // namespace
 
 void SetCrashKeyValue(const base::StringPiece& key,
                       const base::StringPiece& value) {
   if (!g_set_key_func_ || !g_crash_keys_)
@@ skipping 143 matching lines @@
 void ResetCrashLoggingForTesting() {
   delete g_crash_keys_;
   g_crash_keys_ = NULL;
   g_chunk_max_length_ = 0;
   g_set_key_func_ = NULL;
   g_clear_key_func_ = NULL;
 }
 
 }  // namespace debug
 }  // namespace base