Remove unneeded mutable keyword in some member variables

Remove unneeded mutable keyword in some member variables

Some member variables have mutable keyword though they don't used by const function.
This cl removes them.

BUG=N/A

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=170126

[kouhei (in TOK), 2014-03-26 09:22:16]

svg/ non-owner lgtm

[gyuyoung-inactive, 2014-03-26 11:46:02]

The CQ bit was checked by gyuyoung.kim@samsung.com

[commit-bot: I haz the power, 2014-03-26 11:46:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/212183004/30001

[commit-bot: I haz the power, 2014-03-26 11:57:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-26 11:57:51]

Try jobs failed on following builders:
  tryserver.blink on blink_presubmit

[gyuyoung-inactive, 2014-03-26 12:26:23]

On 2014/03/26 11:57:51, I haz the power (commit-bot) wrote:
> Try jobs failed on following builders:
>   tryserver.blink on blink_presubmit

To land a cl, should owner approve a patch ?

** Presubmit ERRORS **
Missing LGTM from an OWNER for these files:
    Source/core/storage/StorageArea.h
    Source/core/svg/animation/SVGSMILElement.h

[gyuyoung-inactive, 2014-03-27 01:02:42]

On 2014/03/26 12:26:23, gyuyoung wrote:
> On 2014/03/26 11:57:51, I haz the power (commit-bot) wrote:
> > Try jobs failed on following builders:
> >   tryserver.blink on blink_presubmit
> 
> To land a cl, should owner approve a patch ?
> 
> ** Presubmit ERRORS **
> Missing LGTM from an OWNER for these files:
>     Source/core/storage/StorageArea.h
>     Source/core/svg/animation/SVGSMILElement.h


> To land a cl, should owner approve a patch ?

I meant the files owner.

[gyuyoung-inactive, 2014-03-27 02:54:02]

Add chris to reviewer as well.

[Inactive, 2014-03-27 03:10:13]

lgtm

[commit-bot: I haz the power, 2014-03-27 03:10:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/gyuyoung.kim@samsung.com/212183004/30001

[commit-bot: I haz the power, 2014-03-27 03:21:55]

Change committed as 170126