Reorder browser list on workspace switch

chrome/browser/ui/browser_list.cc

Index: chrome/browser/ui/browser_list.cc
diff --git a/chrome/browser/ui/browser_list.cc b/chrome/browser/ui/browser_list.cc
index 5516e79a2d661b03360ed12af48582c656e1ed4b..3dee769bb4259b714792dc3e78c686c072635170 100644
--- a/chrome/browser/ui/browser_list.cc
+++ b/chrome/browser/ui/browser_list.cc
@@ -217,9 +217,48 @@ bool BrowserList::IsOffTheRecordSessionActiveForProfile(Profile* profile) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// BrowserList, display::DesktopObserver implementation:
+
+void BrowserList::OnWorkspaceChanged(const std::string& new_workspace) {

[Lei Zhang, 2016/06/29 18:30:53]

Isn't BrowserList cross-platform? How does this affect other OSes? Does this not
get called?

[Tom (Use chromium acct), 2016/06/29 20:16:04]

It won't get called, until we eventually add support for Windows or OS X
workspaces.

+  DCHECK_NE(new_workspace, "");

[Lei Zhang, 2016/06/29 18:30:53]

DCHECK(!new_workspace.empty()) ?

[Tom (Use chromium acct), 2016/06/29 20:16:04]

Done.

+
+  Browser* old_last_active = GetLastActive();
+
+  // Reorder the browsers in the list so that the browsers in the new workspace
+  // appear before the browsers in the other workspaces.
+  //
+  // For example, if we have a list of browser-workspace pairs
+  // [{b1, 0}, {b2, 1}, {b3, 0}, {b4, 1}]
+  // and we switch to workspace 1, we want the resulting browser list to look
+  // like [{b2, 1}, {b4, 1}, {b1, 0}, {b3, 0}].
+  BrowserVector in_this_workspace;
+  BrowserVector in_different_workspace;
+  for (Browser* browser : last_active_browsers_) {
+    if (browser->window()->GetWorkspace() == new_workspace)
+      in_this_workspace.push_back(browser);
+    else
+      in_different_workspace.push_back(browser);
+  }
+  last_active_browsers_.clear();
+  last_active_browsers_.insert(last_active_browsers_.end(),
+                               in_different_workspace.begin(),
+                               in_different_workspace.end());
+  last_active_browsers_.insert(last_active_browsers_.end(),
+                               in_this_workspace.begin(),
+                               in_this_workspace.end());
+
+  Browser* new_last_active = GetLastActive();
+  if (old_last_active != new_last_active) {
+    FOR_EACH_OBSERVER(chrome::BrowserListObserver, observers_.Get(),
+                      OnBrowserSetLastActive(new_last_active));
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
 // BrowserList, private:
 
 BrowserList::BrowserList() {
+  display::g_desktop_observer_list.AddObserver(this);
 }
 
 BrowserList::~BrowserList() {

[Elliot Glaysher, 2016/06/29 18:21:09]

Do you need a matched RemoveObserver?

[Tom (Use chromium acct), 2016/06/29 20:16:04]

Done.