Fixed problems with initial locale change freezing Chrome OS on the device....

Fixed problems with initial locale change freezing Chrome OS on the device.
Added creation of /home/chronos/.oobe_completed flag file.
Removed command line switches for testing customization manifests.
Added StringFetcher class implementation - URL fetcher that downloads content into std::string.
Refactored services customization integration.
Removed sample manifests from Chrome repository. They are submitted into Chromium OS repository at chromeos/src/platform/assets/oem_customization.

Landed in:
http://codereview.chromium.org/2878056

BUG=http://crosbug.com/1888
TEST=Manual. Changes to OEM customization manifests on partner partition, namely the initial locale, time zone, and startup page attributes should change OOBE UX accordingly.

[Nikita (slow), 2010-07-19 12:31:19]

http://codereview.chromium.org/3026006/diff/1/5
File chrome/browser/chromeos/login/string_fetcher.cc (right):

http://codereview.chromium.org/3026006/diff/1/5#newcode14
chrome/browser/chromeos/login/string_fetcher.cc:14: GURL url(url_str);
check that URL is valid?

http://codereview.chromium.org/3026006/diff/1/5#newcode43
chrome/browser/chromeos/login/string_fetcher.cc:43: result_ = data;
You should call a delegate (wizard) on the event when manifest has been fetched.

http://codereview.chromium.org/3026006/diff/1/6
File chrome/browser/chromeos/login/string_fetcher.h (right):

http://codereview.chromium.org/3026006/diff/1/6#newcode17
chrome/browser/chromeos/login/string_fetcher.h:17: // Initiates URL fetch.
Optional auth_token could be passed.
auth_token is not passed.

http://codereview.chromium.org/3026006/diff/1/6#newcode38
chrome/browser/chromeos/login/string_fetcher.h:38: // Fetch result.
empty line between definitions.

http://codereview.chromium.org/3026006/diff/1/7
File chrome/browser/chromeos/login/wizard_controller.cc (right):

http://codereview.chromium.org/3026006/diff/1/7#newcode60
chrome/browser/chromeos/login/wizard_controller.cc:60: // TODO(denisromanov):
Change this to real URL when it becomes available.
Please file issue to track this and mention it here.

http://codereview.chromium.org/3026006/diff/1/7#newcode171
chrome/browser/chromeos/login/wizard_controller.cc:171:
controller->ApplyPartnerServicesCustomizations();
It seems like a not the best place to apply these customizations. It will have
extensions and apps defined which take time to download so it should be done as
early as possible. Doing that right before the browser launch may slow down it.

At best it should be done in parallel.

http://codereview.chromium.org/3026006/diff/1/7#newcode363
chrome/browser/chromeos/login/wizard_controller.cc:363: LOG(INFO) << "WTF: " <<
(is_out_of_box_ ? "out" : "in");
Debug info - should be removed?
At least place a descriptive info message. :)

http://codereview.chromium.org/3026006/diff/1/7#newcode367
chrome/browser/chromeos/login/wizard_controller.cc:367:
services_manifest_fetcher_.reset(new StringFetcher(
We're fetching manifest during OOBE
welcome-update-eula screens.

What if being at sign in screen user shutdowns device?
After restart it won't be OOBE mode part 1.
It will be OOBE part 2 (Register screen after sign in).
OOBE p2 is before .oobe_completed file is written.

We should make sure that services customization will be applied.

http://codereview.chromium.org/3026006/diff/1/7#newcode611
chrome/browser/chromeos/login/wizard_controller.cc:611: }
apps + exts + support page?

http://codereview.chromium.org/3026006/diff/1/7#newcode726
chrome/browser/chromeos/login/wizard_controller.cc:726: if
(file_util::PathExists(startup_manifest_path)) {
Please add check that startup manifest should exist before .oobe_completed file
is created (before both parts of OOBE are finished).

http://codereview.chromium.org/3026006/diff/1/7#newcode736
chrome/browser/chromeos/login/wizard_controller.cc:736:
chromeos::CrosLibrary::Get()->GetLoginLibrary()->EmitLoginPromptReady();
We should look deeper into it.
Emitting login_prompt_ready signal here might slowdown showing login window. See
discussion here
http://code.google.com/p/chromium-os/issues/detail?id=4562

[Nikita (slow), 2010-07-19 12:54:25]

http://codereview.chromium.org/3026006/diff/1/7
File chrome/browser/chromeos/login/wizard_controller.cc (right):

http://codereview.chromium.org/3026006/diff/1/7#newcode736
chrome/browser/chromeos/login/wizard_controller.cc:736:
chromeos::CrosLibrary::Get()->GetLoginLibrary()->EmitLoginPromptReady();
Possible solution:
1. Change Chrome locale only, show welcome screen
2. Postpone switching system wide locale till underlying services are ready
(login_prompt_ready emitted).

With this solution it's fine to leave emitting login_prompt_ready after
controller->Show() as it was. 
In all cases for non-OOBE case it should be leaved unchanged.