Use extension-based file picker from CrOS for Aura builds.

Aura: Use extension-based file picker from CrOS for pure-views builds.

Removes the dependency on chromeos-specific code in the extension-based file picker.  Compiles, links, and runs, but the dialog doesn't function yet - there's still some work to do to wire up the private JavaScript API calls.  See crbug.com/97424

BUG=chromium-os:20583
TEST=On plain ChromeOS, can still open a file with control-O file picker.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=102113

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=102156

[James Cook, 2011-09-19 22:07:47]

Zel, can you look at, or suggest another reviewer for, the changes in
preferences, switches, and extension_file_browser_api.* ?

Emmanuel, please take a look at build/common.gypi and chrome/browser/ui/*

[Emmanuel Saint-loubert-Bié, 2011-09-19 22:29:10]

> Emmanuel, please take a look at build/common.gypi and chrome/browser/ui/*
LGTM. Thanks.

[James Cook, 2011-09-20 18:21:49]

Robert, could you look at the changes in
preferences, switches, and extension_file_browser_api.* ?  I suspect Zel is
swamped with perf, etc.

[rginda, 2011-09-20 23:25:52]

On 2011/09/20 18:21:49, James Cook (Chromium) wrote:
> Robert, could you look at the changes in
> preferences, switches, and extension_file_browser_api.* ?  I suspect Zel is
> swamped with perf, etc.

This LGTM, happy to see the code turned on somewhere other than OS_CHROMEOS :)