[Sync] Split DirectoryChangeListener for thread-safety

[Sync] Split DirectoryChangeListener for thread-safety

Split DirectoryChangeListener into DirectoryChangeDelegate and
TransactionObserver classes.  This removes a remove/notify race
condition with the DirectoryChange events.

Make syncable::{Read,Write}Transaction take Locations instead of
file/line pairs.

Move construction of sync_manager_ into sync thread.

Add logging utils in sync/logging.{h,cc}.

Add overloads to ObserverListThreadSafe::Notify for 2, 3, and 4
arguments.

Fixed 'Inital' misspelling in SyncBackendHost (finally).

BUG=85656
TEST=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=89413

[akalin, 2011-06-16 01:05:59]

+tim for review

Don't be alarmed; most of the files only change __FILE__, __LINE__ to FROM_HERE.

[akalin, 2011-06-16 03:09:13]

+willchan for base stuff

[willchan no longer on Chromium, 2011-06-16 09:50:17]

base/ LGTM

http://codereview.chromium.org/7190001/diff/4006/base/observer_list_threadsafe.h
File base/observer_list_threadsafe.h (right):

http://codereview.chromium.org/7190001/diff/4006/base/observer_list_threadsaf...
base/observer_list_threadsafe.h:151: void Notify(Method m, const A &a) {
http://dev.chromium.org/developers/coding-style#TOC-Code-formatting

I know you're just copying what was there before, but it was wrong. Can you fix
this instance too?

[akalin, 2011-06-16 20:08:33]

http://codereview.chromium.org/7190001/diff/4006/base/observer_list_threadsafe.h
File base/observer_list_threadsafe.h (right):

http://codereview.chromium.org/7190001/diff/4006/base/observer_list_threadsaf...
base/observer_list_threadsafe.h:151: void Notify(Method m, const A &a) {
On 2011/06/16 09:50:17, willchan wrote:
> http://dev.chromium.org/developers/coding-style#TOC-Code-formatting
> 
> I know you're just copying what was there before, but it was wrong. Can you
fix
> this instance too?

Done.

[tim (not reviewing), 2011-06-16 21:10:58]

LGTM

http://codereview.chromium.org/7190001/diff/6051/chrome/browser/sync/glue/syn...
File chrome/browser/sync/glue/sync_backend_host.h (right):

http://codereview.chromium.org/7190001/diff/6051/chrome/browser/sync/glue/syn...
chrome/browser/sync/glue/sync_backend_host.h:506: const std::string name_;
what is |name_|? name of what?

http://codereview.chromium.org/7190001/diff/6051/chrome/browser/sync/glue/syn...
chrome/browser/sync/glue/sync_backend_host.h:515:
scoped_ptr<sync_api::SyncManager> sync_manager_;
I prefer the old name :\ but if you really want to change it shouldn't we change
it everywhere lest we make things more confusing? one example - ui_model_worker
still refers to it as "syncapi"

http://codereview.chromium.org/7190001/diff/6051/chrome/test/sync/null_direct...
File chrome/test/sync/null_directory_change_delegate.h (right):

http://codereview.chromium.org/7190001/diff/6051/chrome/test/sync/null_direct...
chrome/test/sync/null_directory_change_delegate.h:14: class
NullDirectoryChangeDelegate : public DirectoryChangeDelegate {
add class comment

[akalin, 2011-06-16 22:23:12]

Addressed comments, committing.

http://codereview.chromium.org/7190001/diff/6051/chrome/browser/sync/glue/syn...
File chrome/browser/sync/glue/sync_backend_host.h (right):

http://codereview.chromium.org/7190001/diff/6051/chrome/browser/sync/glue/syn...
chrome/browser/sync/glue/sync_backend_host.h:506: const std::string name_;
On 2011/06/16 21:10:58, timsteele wrote:
> what is |name_|? name of what?

Done.

http://codereview.chromium.org/7190001/diff/6051/chrome/browser/sync/glue/syn...
chrome/browser/sync/glue/sync_backend_host.h:515:
scoped_ptr<sync_api::SyncManager> sync_manager_;
On 2011/06/16 21:10:58, timsteele wrote:
> I prefer the old name :\ but if you really want to change it shouldn't we
change
> it everywhere lest we make things more confusing? one example -
ui_model_worker
> still refers to it as "syncapi"

Well, the problem with the name "syncapi" is that it's overloaded.  Here it was
used to mean "instance of the SyncManager class", in ui_model_worker, according
to the comments, it's really referring to the sync *thread*, and in other places
(DirectoryChangeDelegate) it's used to mean "from Chrome" as opposed to "from
the cloud".

I'll fix ui_model_worker et al. in a separate CL.

http://codereview.chromium.org/7190001/diff/6051/chrome/test/sync/null_direct...
File chrome/test/sync/null_directory_change_delegate.h (right):

http://codereview.chromium.org/7190001/diff/6051/chrome/test/sync/null_direct...
chrome/test/sync/null_directory_change_delegate.h:14: class
NullDirectoryChangeDelegate : public DirectoryChangeDelegate {
On 2011/06/16 21:10:58, timsteele wrote:
> add class comment

Done.