Creates BrowserTabStripTracker to consolidate common code

Creates BrowserTabStripTracker to consolidate common code

There are a handful of places that attach a TabStripModelObserver to a
subset of Browsers. This patch consolidates that.

BUG=none
TEST=none
R=pkasting@chromium.org

Committed: https://crrev.com/dbc6f296c6661dc416e21194e69a3ee4bae51a6d
Cr-Commit-Position: refs/heads/master@{#353532}

[Peter Kasting, 2015-10-10 00:34:40]

LGTM.  Nice, this makes the consumers noticeably cleaner.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/extensions/a...
File chrome/browser/extensions/api/tabs/tabs_event_router.h (right):

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/extensions/a...
chrome/browser/extensions/api/tabs/tabs_event_router.h:52: //
chrome::BrowserListObserver
Nit: While here: Colons on these class names?

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/ash/metri...
File chrome/browser/ui/ash/metrics/chrome_user_metrics_recorder.h (left):

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/ash/metri...
chrome/browser/ui/ash/metrics/chrome_user_metrics_recorder.h:23: //
chrome::BroswerListObserver:
Yay for free bonus removal of a misspelling!

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
File chrome/browser/ui/browser_tab_strip_tracker.cc (right):

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.cc:36: switch (init_with) {
Nit: I kinda feel like just an if (...) { } else { } would be fine

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.cc:43: for (chrome::BrowserIterator
it; !it.done(); it.Next())
Random grouse: It sure would be nice if we redid these iterators' syntax so they
could use range-based for!

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.cc:73: // GlobalConfirmInfoBar (in
debugger_api) wants this.
Nit: Not totally clear on what this comment means... is it saying this is a
temporary thing and will go away later?

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
File chrome/browser/ui/browser_tab_strip_tracker.h (right):

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:25: // If you are interested in
BrowserListObserver functions  specify a
Nit: Two spaces (was a comma intended?)

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:40: explicit
BrowserTabStripTracker(
Nit: No explicit needed

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:49: // should be observered. If an
existing Browser should be observed
Nit: observed

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:51: // differentiate between
Browsers observed by way of Init() vs a Browser added
Nit: vs.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:60: // Stops observing the current
set of observered browsers and calls
Nit: observed

[sky, 2015-10-12 15:16:21]

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/extensions/a...
File chrome/browser/extensions/api/tabs/tabs_event_router.h (right):

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/extensions/a...
chrome/browser/extensions/api/tabs/tabs_event_router.h:52: //
chrome::BrowserListObserver
On 2015/10/10 00:34:39, Peter Kasting wrote:
> Nit: While here: Colons on these class names?

Done.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
File chrome/browser/ui/browser_tab_strip_tracker.cc (right):

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.cc:36: switch (init_with) {
On 2015/10/10 00:34:40, Peter Kasting wrote:
> Nit: I kinda feel like just an if (...) { } else { } would be fine

Done.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.cc:43: for (chrome::BrowserIterator
it; !it.done(); it.Next())
On 2015/10/10 00:34:39, Peter Kasting wrote:
> Random grouse: It sure would be nice if we redid these iterators' syntax so
they
> could use range-based for!

Agreed. I'm not trying to do it now though.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.cc:73: // GlobalConfirmInfoBar (in
debugger_api) wants this.
On 2015/10/10 00:34:40, Peter Kasting wrote:
> Nit: Not totally clear on what this comment means... is it saying this is a
> temporary thing and will go away later?

Nuked.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
File chrome/browser/ui/browser_tab_strip_tracker.h (right):

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:25: // If you are interested in
BrowserListObserver functions  specify a
On 2015/10/10 00:34:40, Peter Kasting wrote:
> Nit: Two spaces (was a comma intended?)

Done.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:40: explicit
BrowserTabStripTracker(
On 2015/10/10 00:34:40, Peter Kasting wrote:
> Nit: No explicit needed

Done.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:49: // should be observered. If an
existing Browser should be observed
On 2015/10/10 00:34:40, Peter Kasting wrote:
> Nit: observed

Done.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:51: // differentiate between
Browsers observed by way of Init() vs a Browser added
On 2015/10/10 00:34:40, Peter Kasting wrote:
> Nit: vs.

Done.

https://codereview.chromium.org/1400823003/diff/1/chrome/browser/ui/browser_t...
chrome/browser/ui/browser_tab_strip_tracker.h:60: // Stops observing the current
set of observered browsers and calls
On 2015/10/10 00:34:40, Peter Kasting wrote:
> Nit: observed

Done.

[sky, 2015-10-12 15:16:26]

The CQ bit was checked by sky@chromium.org

[sky, 2015-10-12 15:16:26]

The patchset sent to the CQ was uploaded after l-g-t-m from
pkasting@chromium.org
Link to the patchset: https://codereview.chromium.org/1400823003/#ps20001
(title: "review feedback and git cl format")

[commit-bot: I haz the power, 2015-10-12 15:17:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1400823003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1400823003/20001

[commit-bot: I haz the power, 2015-10-12 16:30:11]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-10-12 16:31:03]

Patchset 2 (id:??) landed as
https://crrev.com/dbc6f296c6661dc416e21194e69a3ee4bae51a6d
Cr-Commit-Position: refs/heads/master@{#353532}