Automatically remap Command key on an Apple keyboard to Control [part 1 of 2 - Ash part]

Automatically remap Command key on an Apple keyboard to Control [part 1 of 2 - Ash part]

Add key_rewriter_event_filter.h which allows its delegate to rewrite or delete an aura::KeyEvent. The new interface will be used for implementing the following three features:

* crosbug.com/25097: Remap keys on external keyboards (R19)
* crosbug.com/27167: Consider adding a way to send function keys to web pages (R20)
* crbug.com/115112: Move modifier remapping code from X to Chrome (M20)

Part 2 of 2: http://codereview.chromium.org/9854025/

BUG=chromium-os:25097
BUG=chromium-os:27167
BUG=115112
TEST=try

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=129076

[Yusuke Sato, 2012-03-26 15:01:50]

Daniel, could you review this?

[Daniel Erat, 2012-03-26 15:40:30]

http://codereview.chromium.org/9838010/diff/12001/ash/key_rewriter_delegate.h
File ash/key_rewriter_delegate.h (right):

http://codereview.chromium.org/9838010/diff/12001/ash/key_rewriter_delegate.h...
ash/key_rewriter_delegate.h:23: virtual bool
RewriteOrFilterKeyEvent(aura::KeyEvent* event) = 0;
i never know what true and false mean in the return values from filtering
methods.  please add an enum to this class instead, like:

  enum Action {
    ACTION_REWRITE_EVENT,
    ACTION_DROP_EVENT,
  };

  virtual Action RewriteKeyEvent(aura::KeyEvent* event) = 0;

it might be better to avoid the word "filter" here to avoid confusion with
EventFilter.

[Yusuke Sato, 2012-03-26 16:06:28]

http://codereview.chromium.org/9838010/diff/12001/ash/key_rewriter_delegate.h
File ash/key_rewriter_delegate.h (right):

http://codereview.chromium.org/9838010/diff/12001/ash/key_rewriter_delegate.h...
ash/key_rewriter_delegate.h:23: virtual bool
RewriteOrFilterKeyEvent(aura::KeyEvent* event) = 0;
On 2012/03/26 15:40:30, Daniel Erat wrote:
> i never know what true and false mean in the return values from filtering
> methods.  please add an enum to this class instead, like:
> 
>   enum Action {
>     ACTION_REWRITE_EVENT,
>     ACTION_DROP_EVENT,
>   };
> 
>   virtual Action RewriteKeyEvent(aura::KeyEvent* event) = 0;
> 
> it might be better to avoid the word "filter" here to avoid confusion with
> EventFilter.

Done.

[Daniel Erat, 2012-03-26 16:18:38]

lgtm