CHECK to only receive touch/gesture events in touch selection tests

Added a CHECK in touch selection tests to make sure that we only receive
touch or gesture events. Currently, some touch selection tests are flaky
because sometimes they receive unexpected mouse events that end touch
selection in the middle of the test. This CHECK will give us stack trace
to investigate the situation.

Previous review URL: https://codereview.chromium.org/26275005/

BUG=235991,276870

Review URL: https://codereview.chromium.org/27617002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230506 0039d316-1c4b-4281-b951-d872f2087c98
Always initialize data reduction proxy pref member

The settings UI code may check a BooleanPrefMember in DataReductionProxySettings even when the Chrome instance is not part of a field trial that allows it to be used. If the pref member is not initialized, Chrome will Crash.

BUG=309213

Review URL: https://codereview.chromium.org/29363010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230507 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230506
Move Navigation.MainFrameScheme UMA recording to //components.

This change is simply a refactoring, and does not change behavior.

BUG=299173
TEST=Run chromium, check about:histograms and make sure that Navigation.MainFrameScheme matches expectations.

Review URL: https://codereview.chromium.org/35693009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230508 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230508