Adding UMA count for number of logical processors on Windows.

I need to merge this into m30 or even m29 so trying to find a happy place to gather this.

It can be found as Platform.LogicalCpuCount

BUG=none
TBR=sky
TEST=none

Review URL: https://codereview.chromium.org/25647002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228020 0039d316-1c4b-4281-b951-d872f2087c98
Fix ExtensionSet's const-input-iterator.

It subclasses std::iterator<std::input_iterator_tag, ...> and thus must respect http://www.cplusplus.com/reference/iterator/InputIterator/.

It is also a const-iterator and thus every method, but the pre/post-increments should be const.

Review URL: https://codereview.chromium.org/26265002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228021 0039d316-1c4b-4281-b951-d872f2087c98
Avoid crash in OnRequestThumbnailForContextNode by not processing null pointer.

BUG=274832

Review URL: https://codereview.chromium.org/26477004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228022 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228021
Remove override_encoding from NavigateParams and OpenURLParams.

It's unused and doesn't do anything.

BUG=none
TEST=compiles

Review URL: https://codereview.chromium.org/26606003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228023 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228022
SVN changes up to revision 228023