Creates BrowserTabStripTracker to consolidate common code

chrome/browser/ui/browser_tab_strip_tracker.cc

Index: chrome/browser/ui/browser_tab_strip_tracker.cc
diff --git a/chrome/browser/ui/browser_tab_strip_tracker.cc b/chrome/browser/ui/browser_tab_strip_tracker.cc
new file mode 100644
index 0000000000000000000000000000000000000000..298b957b2c02d3926945490b3e2b04566bfae885
--- /dev/null
+++ b/chrome/browser/ui/browser_tab_strip_tracker.cc
@@ -0,0 +1,102 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/ui/browser_tab_strip_tracker.h"
+
+#include "base/auto_reset.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_iterator.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_tab_strip_tracker_delegate.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+
+BrowserTabStripTracker::BrowserTabStripTracker(
+    TabStripModelObserver* tab_strip_model_observer,
+    BrowserTabStripTrackerDelegate* delegate,
+    BrowserListObserver* browser_list_observer)
+    : tab_strip_model_observer_(tab_strip_model_observer),
+      delegate_(delegate),
+      browser_list_observer_(browser_list_observer),
+      is_processing_initial_browsers_(false) {
+  DCHECK(tab_strip_model_observer_);
+}
+
+BrowserTabStripTracker::~BrowserTabStripTracker() {
+  for (Browser* browser : browsers_observing_)
+    browser->tab_strip_model()->RemoveObserver(tab_strip_model_observer_);
+
+  BrowserList::RemoveObserver(this);
+}
+
+void BrowserTabStripTracker::Init(InitWith init_with) {
+  BrowserList::AddObserver(this);
+
+  base::AutoReset<bool> restter(&is_processing_initial_browsers_, true);
+  switch (init_with) {

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

Nit: I kinda feel like just an if (...) { } else { } would be fine

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

Done.

+    case InitWith::BROWSERS_IN_ACTIVE_DESKTOP:
+      for (Browser* browser :
+           *BrowserList::GetInstance(chrome::GetActiveDesktop()))
+        MaybeTrackBrowser(browser);
+      break;
+    case InitWith::ALL_BROWERS:
+      for (chrome::BrowserIterator it; !it.done(); it.Next())

[Peter Kasting, 2015/10/10 00:34:39]

Random grouse: It sure would be nice if we redid these iterators' syntax so they
could use range-based for!

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

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

+        MaybeTrackBrowser(*it);
+      break;
+  }
+}
+
+void BrowserTabStripTracker::StopObservingAndSendOnBrowserRemoved() {
+  Browsers current_browsers;
+  current_browsers.swap(browsers_observing_);
+
+  for (Browser* browser : current_browsers) {
+    browser->tab_strip_model()->RemoveObserver(tab_strip_model_observer_);
+    if (browser_list_observer_)
+      browser_list_observer_->OnBrowserRemoved(browser);
+  }
+}
+
+bool BrowserTabStripTracker::ShouldTrackBrowser(Browser* browser) {
+  return !delegate_ || delegate_->ShouldTrackBrowser(browser);
+}
+
+void BrowserTabStripTracker::MaybeTrackBrowser(Browser* browser) {
+  if (!ShouldTrackBrowser(browser))
+    return;
+
+  browsers_observing_.insert(browser);
+
+  if (browser_list_observer_)
+    browser_list_observer_->OnBrowserAdded(browser);
+
+  // GlobalConfirmInfoBar (in debugger_api) wants this.

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

Nit: Not totally clear on what this comment means... is it saying this is a
temporary thing and will go away later?

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

Nuked.

+  TabStripModel* tab_strip_model = browser->tab_strip_model();
+  tab_strip_model->AddObserver(tab_strip_model_observer_);
+  const int active_index = tab_strip_model->active_index();
+  for (int i = 0; i < tab_strip_model->count(); ++i) {
+    tab_strip_model_observer_->TabInsertedAt(
+        tab_strip_model->GetWebContentsAt(i), i, i == active_index);
+  }
+}
+
+void BrowserTabStripTracker::OnBrowserAdded(Browser* browser) {
+  MaybeTrackBrowser(browser);
+}
+
+void BrowserTabStripTracker::OnBrowserRemoved(Browser* browser) {
+  auto it = browsers_observing_.find(browser);
+  if (it == browsers_observing_.end())
+    return;
+
+  browsers_observing_.erase(it);
+  browser->tab_strip_model()->RemoveObserver(tab_strip_model_observer_);
+
+  if (browser_list_observer_)
+    browser_list_observer_->OnBrowserRemoved(browser);
+}
+
+void BrowserTabStripTracker::OnBrowserSetLastActive(Browser* browser) {
+  if (browser_list_observer_)
+    browser_list_observer_->OnBrowserSetLastActive(browser);
+}