Add AppWindow.setVisibleOnAllWorkspaces.

chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm

Index: chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
index 691de9aaefe05eb44cedc4c42d5447bd8069d532..757e36ca95d0619d32f0c1103a97de709e98d319 100644
--- a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
@@ -60,6 +60,15 @@ void SetFullScreenCollectionBehavior(NSWindow* window, bool allow_fullscreen) {
   [window setCollectionBehavior:behavior];
 }
 
+void SetWorkspacesCollectionBehavior(NSWindow* window, bool always_visible) {
+  NSWindowCollectionBehavior behavior = [window collectionBehavior];
+  if (always_visible)
+    behavior |= NSWindowCollectionBehaviorCanJoinAllSpaces;
+  else
+    behavior &= ~NSWindowCollectionBehaviorCanJoinAllSpaces;
+  [window setCollectionBehavior:behavior];
+}
+
 void InitCollectionBehavior(NSWindow* window) {
   // Since always-on-top windows have a higher window level
   // than NSNormalWindowLevel, they will default to
@@ -379,6 +388,8 @@ NativeAppWindowCocoa::NativeAppWindowCocoa(
     [window setLevel:AlwaysOnTopWindowLevel()];
   InitCollectionBehavior(window);
 
+  SetWorkspacesCollectionBehavior(window, params.visible_on_all_workspaces);
+
   window_controller_.reset(
       [[NativeAppWindowController alloc] initWithWindow:window.release()]);
 
@@ -967,6 +978,10 @@ void NativeAppWindowCocoa::SetAlwaysOnTop(bool always_on_top) {
                                       NSNormalWindowLevel)];
 }
 
+void NativeAppWindowCocoa::SetVisibleOnAllWorkspaces(bool always_visible) {
+  SetWorkspacesCollectionBehavior(window(), always_visible);
+}
+
 NativeAppWindowCocoa::~NativeAppWindowCocoa() {
 }