Only overwrite DomKey of keydown event if it's a printable character

Only overwrite DomKey of keydown event if it's a printable character

InputMethodWin will combine the WM_KEY* and WM_CHAR messages, and will
overwrite DomKey for |keydown| with the DomKey of |keypress|.

We want to only overwite it if the new DomKey is not a control
character.

BUG=601882
Review URL: https://codereview.chromium.org/1875763003

Cr-Commit-Position: refs/heads/master@{#386691}
(cherry picked from commit 19ec26442db050a055cf9f9486aa69db4bd70cf1)

Committed: https://chromium.googlesource.com/chromium/src/+/ebe05dfa595ef8688ff8f10eac850821ed095de2

[dtapuska, 2016-04-27 16:20:12]

Description was changed from

==========
Only overwrite DomKey of keydown event if it's a printable character

InputMethodWin will combine the WM_KEY* and WM_CHAR messages, and will
overwrite DomKey for |keydown| with the DomKey of |keypress|.

We want to only overwite it if the new DomKey is not a control
character.

BUG=601882

Review URL: https://codereview.chromium.org/1875763003

Cr-Commit-Position: refs/heads/master@{#386691}
(cherry picked from commit 19ec26442db050a055cf9f9486aa69db4bd70cf1)
==========

to

==========
Only overwrite DomKey of keydown event if it's a printable character

InputMethodWin will combine the WM_KEY* and WM_CHAR messages, and will
overwrite DomKey for |keydown| with the DomKey of |keypress|.

We want to only overwite it if the new DomKey is not a control
character.

BUG=601882

Review URL: https://codereview.chromium.org/1875763003

Cr-Commit-Position: refs/heads/master@{#386691}
(cherry picked from commit 19ec26442db050a055cf9f9486aa69db4bd70cf1)

Committed:
https://chromium.googlesource.com/chromium/src/+/ebe05dfa595ef8688ff8f10eac85...
==========

[dtapuska, 2016-04-27 16:20:14]

Committed patchset #1 (id:1) manually as
ebe05dfa595ef8688ff8f10eac850821ed095de2.