Brushes up the code of screenshot filename.

Brushes up the code of screenshot filename.

Currently it just checks the filename duplication and adding numbers (1),(2),... in
case of duplication.  But this doesn't work well if the file will be stored into GoogleDrive,
since file operations are not atomic there.  

This CL does the followings:
- the screenshot taker accepts "taking a screenshot for each root window" requests
  rather than taking a screenshot for the specified window
- adding the number in case of multiple root-windows, in screenshot taker side
- change the screenshot interval from 500msec -> 1sec, to avoid the duplication
- remove the existing filename duplication checking code, which is no longer necessary

BUG=140749
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=150758

[kinaba, 2012-08-07 05:01:30]

LGTM with a nit.

http://codereview.chromium.org/10827193/diff/1/chrome/browser/ui/ash/screensh...
File chrome/browser/ui/ash/screenshot_taker.cc (right):

http://codereview.chromium.org/10827193/diff/1/chrome/browser/ui/ash/screensh...
chrome/browser/ui/ash/screenshot_taker.cc:148: // "base_name.png" already
exists.
We can remove this comment.

[Jun Mukai, 2012-08-07 05:03:27]

http://codereview.chromium.org/10827193/diff/1/chrome/browser/ui/ash/screensh...
File chrome/browser/ui/ash/screenshot_taker.cc (right):

http://codereview.chromium.org/10827193/diff/1/chrome/browser/ui/ash/screensh...
chrome/browser/ui/ash/screenshot_taker.cc:148: // "base_name.png" already
exists.
On 2012/08/07 05:01:30, kinaba wrote:
> We can remove this comment.

Done.

[Jun Mukai, 2012-08-08 01:17:31]

derat, can you take a look at this as the OWNER of ash?

[Daniel Erat, 2012-08-08 16:33:08]

lgtm

http://codereview.chromium.org/10827193/diff/2003/ash/accelerators/accelerato...
File ash/accelerators/accelerator_controller.cc (right):

http://codereview.chromium.org/10827193/diff/2003/ash/accelerators/accelerato...
ash/accelerators/accelerator_controller.cc:443:
screenshot_delegate_->CanTakeScreenshot())
nit: add curly braces since if condition is two lines

[Jun Mukai, 2012-08-09 04:40:35]

http://codereview.chromium.org/10827193/diff/2003/ash/accelerators/accelerato...
File ash/accelerators/accelerator_controller.cc (right):

http://codereview.chromium.org/10827193/diff/2003/ash/accelerators/accelerato...
ash/accelerators/accelerator_controller.cc:443:
screenshot_delegate_->CanTakeScreenshot())
On 2012/08/08 16:33:08, Daniel Erat wrote:
> nit: add curly braces since if condition is two lines

Done.