Fix a crash which occurs while translating the windows message WM_DEADCHAR to our events format.
The crash occurs because the EventTypeFromNative helper function on windows does not handle this
message and returns ET_UNKNOWN as the type leading to a CHECK later on. The WM_DEADCHAR message
is posted while translating certain character sequences in the context of WM_KEYUP.
Fix is to return the type for WM_DEADCHAR as ET_KEY_RELEASED.
BUG=411811
Review URL: https://codereview.chromium.org/
551863003
Cr-Commit-Position: refs/heads/master@{#293859}