Don't pull in content_switches.cc to whole chrome code base

The point of this change is remove compilation of content_switches.cc
that was done in installer_util target. This is a static library
that other parts of chrome pull in and that makes the Chrome code that
references those switches compile even if the switches itself are
not exported.
Installer_util doesn't even seem to uses those switches AFAIK.

Dropped compilation of these files so these problems are actually
exposed and addressed by the person adding the switch. The main
offender that referenced those switches was chrome's about_flags.cc.

BUG=

Review URL: https://codereview.chromium.org/24994002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226921 0039d316-1c4b-4281-b951-d872f2087c98
Add Renderer4.InvalidationRegion* uma stat to histograms

R=isherman@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/25353008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226922 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226921
Factors out showing tooltip functionality into standalone class

I'm doing this so that I can create a windows specific tooltip
implementation that uses native tooltips.

BUG=292738
TEST=none
R=varunjain@chromium.org

Review URL: https://codereview.chromium.org/25737003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226923 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226923
cc: Stop using magic numbers to detect if we can use partial updates.

We were using size_t's max value to detect if we can always use
partial updates, but this is pretty magical. Instead, enable it when
1) The renderer allows partial updates at all (not ubercomp), and
2) Using single thread proxy.

R=reveman@chromium.org
BUG=234233

Review URL: https://codereview.chromium.org/25912003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226924 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226924