Simplify update error message support HTML.

Simplify update error message support HTML.

Errors from the update mechanism were appearing twice, once
included in the error string generated in google_update_win
and once in OnError() of version_updater_win.  This caused
redundant information like this:

Update failed (error: 1)An error occurred while checking for updates: Update check failed to start (error code 1: 0x80004005).

Now this:

An error occurred while checking for updates: Update check failed to start (error code 1: 0x80004005).

In addition, this allows removal of the check against a specific
error code since that comes with an actual error message already.

The error message has been explicitly stated as being HTML, making
it okay for callers to include mark-up such as links to more info.

For more information, see the discussion on this CL:
https://codereview.chromium.org/1212783003/

BUG=489801
Committed: https://crrev.com/5895b1965309229401de2afc2c815890d51ff4f5
Cr-Commit-Position: refs/heads/master@{#338282}

[bcwhite, 2015-07-07 00:17:13]

bcwhite@chromium.org changed reviewers:
+ grt@chromium.org

[bcwhite, 2015-07-08 19:20:54]

Greg, I know you're not an owner for any of this, but is this okay with you?

[grt (UTC plus 2), 2015-07-09 14:33:10]

much nicer error message. lgtm with a comment suggestion.

https://codereview.chromium.org/1214603005/diff/20001/chrome/browser/google/g...
File chrome/browser/google/google_update_win.h (right):

https://codereview.chromium.org/1214603005/diff/20001/chrome/browser/google/g...
chrome/browser/google/google_update_win.h:81: // should include the error code
because that will not be displayed otherwise.
Ideally, this comment should explain the contract for both implementors and
consumers. How about:

"|html_error_message|, if not empty, must be a localized string containing all
information required by users to act on the error as well as for support staff
to diagnose it (i.e., |error_code| and any other related state)."

[bcwhite, 2015-07-09 14:54:01]

https://codereview.chromium.org/1214603005/diff/20001/chrome/browser/google/g...
File chrome/browser/google/google_update_win.h (right):

https://codereview.chromium.org/1214603005/diff/20001/chrome/browser/google/g...
chrome/browser/google/google_update_win.h:81: // should include the error code
because that will not be displayed otherwise.
On 2015/07/09 14:33:09, grt wrote:
> Ideally, this comment should explain the contract for both implementors and
> consumers. How about:
> 
> "|html_error_message|, if not empty, must be a localized string containing all
> information required by users to act on the error as well as for support staff
> to diagnose it (i.e., |error_code| and any other related state)."

Done.

[bcwhite, 2015-07-09 14:55:39]

The CQ bit was checked by bcwhite@chromium.org to run a CQ dry run

[bcwhite, 2015-07-09 14:55:39]

The patchset sent to the CQ was uploaded after l-g-t-m from grt@chromium.org
Link to the patchset: https://codereview.chromium.org/1214603005/#ps40001
(title: "comment improvement")

[commit-bot: I haz the power, 2015-07-09 14:56:10]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1214603005/40001

[bcwhite, 2015-07-09 14:56:45]

bcwhite@chromium.org changed reviewers:
+ pkasting@chromium.org

[commit-bot: I haz the power, 2015-07-09 15:05:12]

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

[commit-bot: I haz the power, 2015-07-09 15:05:13]

Dry run: This issue passed the CQ dry run.

[Peter Kasting, 2015-07-09 21:18:39]

lgtm

[bcwhite, 2015-07-10 12:39:17]

The CQ bit was checked by bcwhite@chromium.org

[commit-bot: I haz the power, 2015-07-10 12:39:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1214603005/40001

[commit-bot: I haz the power, 2015-07-10 12:43:39]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-07-10 12:44:34]

Patchset 3 (id:??) landed as
https://crrev.com/5895b1965309229401de2afc2c815890d51ff4f5
Cr-Commit-Position: refs/heads/master@{#338282}