Fix the tab dragging issue seen with maximized chrome windows in the recent Canaries.

Turned out to be a fallout from hiding the scrollbars in the OnEnterSizeMove function which is invoked via the message
WM_ENTERSIZEMOVE. This message as the name suggests also comes in for regular moves or window drags. Hiding the scrollbar
lead to badness with subsequent paints.

Fix is to detect if we are in a sizing operation and set a flag indicating the same. The OnEnterSizeMove and OnExitSizeMove
handlers continue hiding the scrollbars and readding the scroll styles as before. The flag is set and reset in OnSysCommand
for sizing operations.

BUG=336325
R=cpu@chromium.org, sky@chromium.org, sky

Review URL: https://codereview.chromium.org/141003016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246473 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246473
LogMessage::Init must check untrusted severity_ value before using it as an array index.

Another common case hit with the IPC fuzzer, and easy to handle.
BUG=329723

Review URL: https://codereview.chromium.org/138953003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246474 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246474