GYP variable v8_optimized_debug should be overridable by GYP_DEFINES

This re-lands r226772. The issue that caused the revert has been fixed on the V8 side.

Review URL: https://codereview.chromium.org/27708002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229634 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229634
Fix Win8 skin for the new avatar button.

Screenshot: https://docs.google.com/file/d/0B1B1Up4p2NRMUTQ3ZzM1TlMwZWM/edit?usp=sharing

BUG=287883

Review URL: https://codereview.chromium.org/27710003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229635 0039d316-1c4b-4281-b951-d872f2087c98
[Files.app] Put a temporary action item to the file contextmenu until task is loaded

Tasks are loaded asynchronously when the context menu is requested to show. The size of menu might be changed after the menu calculates the geometry and the position so the bottom part of the menu might be hidden because the menu expanded.

This patch adds a temporary action item to the file context menu so the menu doesn't expand and a part of it is not hidden.

BUG=290390
TEST=manually tested

Review URL: https://codereview.chromium.org/27713002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229636 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229635
Enables system key functionality on the virtual keyboard. Note the power button currently does not get propagated correctly. It is blocked due to chromoting (crbug/146609). This will be addressed in a later patch.

BUG=297103

Review URL: https://codereview.chromium.org/27721004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229637 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229637