Fix a warning in 64bit c++11 mode.

Fix a warning in 64bit c++11 mode.

The (harmless) warning was:

../../webkit/plugins/ppapi/message_channel.cc:286:69: error: comparison of constant 2305843009213693951 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
      if (std::numeric_limits<size_t>::max() / sizeof(NPIdentifier) <=
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
1 error generated.

It's always false in 64bit mode, but it's arguably useful in 32bit mode.

BUG=233330
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=195026

[Nico, 2013-04-18 23:06:21]

cc cdn, who added this condition.

[piman, 2013-04-18 23:11:36]

https://codereview.chromium.org/14246019/diff/1/webkit/plugins/ppapi/message_...
File webkit/plugins/ppapi/message_channel.cc (right):

https://codereview.chromium.org/14246019/diff/1/webkit/plugins/ppapi/message_...
webkit/plugins/ppapi/message_channel.cc:287: static_cast<size_t>(*count + 1)) 
// Else, "always false" x64 warning.
paranoid in me: static_cast<size_t>(*count) + 1 ?
That way we don't risk wrap before casting.

[Nico, 2013-04-18 23:13:52]

https://codereview.chromium.org/14246019/diff/1/webkit/plugins/ppapi/message_...
File webkit/plugins/ppapi/message_channel.cc (right):

https://codereview.chromium.org/14246019/diff/1/webkit/plugins/ppapi/message_...
webkit/plugins/ppapi/message_channel.cc:287: static_cast<size_t>(*count + 1)) 
// Else, "always false" x64 warning.
On 2013/04/18 23:11:36, piman wrote:
> paranoid in me: static_cast<size_t>(*count) + 1 ?
> That way we don't risk wrap before casting.

Done.

[piman, 2013-04-18 23:51:59]

lgtm

[Nico, 2013-04-19 00:13:54]

Committed patchset #2 manually as r195026.