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..d94fd697ce3cd2dd8fe75a2f96c917b0b2539256 100644
--- a/chrome/browser/ui/browser_list.cc
+++ b/chrome/browser/ui/browser_list.cc
@@ -20,6 +20,7 @@
 #include "chrome/browser/ui/browser_window.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/user_metrics.h"
+#include "ui/display/desktop.h"
 
 using base::UserMetricsAction;
 using content::WebContents;
@@ -217,12 +218,52 @@ bool BrowserList::IsOffTheRecordSessionActiveForProfile(Profile* profile) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// BrowserList, display::DesktopObserver implementation:
+
+void BrowserList::OnWorkspaceChanged(const std::string& new_workspace) {
+  DCHECK(!new_workspace.empty());
+
+  Browser* old_last_active = GetLastActive();
+
+  // Reorder 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;
+  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::Desktop::AddObserver(this);
 }
 
 BrowserList::~BrowserList() {
+  display::Desktop::RemoveObserver(this);
 }
 
 // static