athena: Fix switching windows with title-drag in split-view.

athena/wm/split_view_controller.cc

Index: athena/wm/split_view_controller.cc
diff --git a/athena/wm/split_view_controller.cc b/athena/wm/split_view_controller.cc
index 3d0cdcb84a5b98af3afe24dc23e184f7dfe73eb8..078156e2c17155fba8b6b9ada6c1317f545f494c 100644
--- a/athena/wm/split_view_controller.cc
+++ b/athena/wm/split_view_controller.cc
@@ -102,6 +102,24 @@ void SplitViewController::ActivateSplitMode(aura::Window* left,
   UpdateLayout(true);
 }
 
+void SplitViewController::ReplaceWindow(aura::Window* window,
+                                        aura::Window* replace_with) {
+  CHECK(IsSplitViewModeActive());
+  CHECK(replace_with);
+  CHECK(window == left_window_ || window == right_window_);
+  CHECK(replace_with != left_window_ && replace_with != right_window_);
+  CHECK_EQ(container_, window->parent());

[mfomitchev, 2014/08/14 14:38:13]

might make more sense to check that windows belongs to
window_list_provider_->GetWindowList() instead.

[sadrul, 2014/08/15 19:00:19]

Done.

+  CHECK_EQ(container_, replace_with->parent());
+
+  replace_with->SetBounds(window->bounds());
+  replace_with->SetTransform(gfx::Transform());

[mfomitchev, 2014/08/14 14:38:13]

Any reason we wouldn't want to reset the bounds on window to container bounds
and reset the transform to gfx::Transform()? Typically we leave the windows in
untransformed state after we are done with them in SplitViewController.

[sadrul, 2014/08/15 19:00:20]

I added the change to reset the transform on |window|. We shouldn't reset the
bounds, because the user may switch back to the window, and we don't want the
unnecessary re-layouts (e.g. we don't resize all the tabs in chrome when the
window resizes, until the user switches to that window).

[mfomitchev, 2014/08/15 19:15:03]

Acknowledged.

+  if (window == left_window_)
+    left_window_ = replace_with;
+  else
+    right_window_ = replace_with;
+  container_->StackChildAbove(replace_with, window);

[mfomitchev, 2014/08/14 14:38:13]

I think we should use window_list_provider_->MoveToFront() here. Or add
StackAbove() method to WindowListProvider interface if we need to.  Or use
ActivateWindow() and have MruWindowTracker start listening to activations.
Otherwise we'd have the order of the windows in WindowListProvider get out of
sync with the stack-order of the windows in the container.

[sadrul, 2014/08/15 19:00:20]

Done (calling wm::ActivateWindow()).

+}
+
 void SplitViewController::UpdateLayout(bool animate) {
   if  (!left_window_)
     return;