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..2f578b6978d705cd46144e051c5418452a7a200a 100644
--- a/chrome/browser/ui/browser_list.cc
+++ b/chrome/browser/ui/browser_list.cc
@@ -186,6 +186,46 @@ void BrowserList::PostBeforeUnloadHandlers(
 }
 
 // static
+void BrowserList::ReorderAfterWorkspaceChange(
+    const std::string& new_workspace) {
+  DCHECK(!new_workspace.empty());
+
+  BrowserList* instance = GetInstance();
+
+  Browser* old_last_active = instance->GetLastActive();
+  BrowserVector& last_active_browsers = instance->last_active_browsers_;
+
+  // Perform a stable partition on the browsers in the list so that the browsers
+  // in the new workspace appear after 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 [{b1, 0}, {b3, 0}, {b2, 1}, {b4, 1}].
+  BrowserVector in_this_workspace;

[sky, 2016/07/06 20:33:05]

Isn't this the same as a sort with a comparator that looks at workspace?

[Tom (Use chromium acct), 2016/07/06 22:29:16]

Nice catch.  stable_sort is much cleaner

+  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 = instance->GetLastActive();
+  if (old_last_active != new_last_active) {
+    FOR_EACH_OBSERVER(chrome::BrowserListObserver, observers_.Get(),
+                      OnBrowserSetLastActive(new_last_active));
+  }
+}
+
+// static
 void BrowserList::SetLastActive(Browser* browser) {
   content::RecordAction(UserMetricsAction("ActiveBrowserChanged"));