Add a NOT_DRAWN window in between the root_window and its children.

ash/wm/root_window_layout_manager.cc

Index: ash/wm/root_window_layout_manager.cc
diff --git a/ash/wm/root_window_layout_manager.cc b/ash/wm/root_window_layout_manager.cc
index aa7301dd06d485d8d2cf4afb2c37114d9f47cc09..55cce76ad490e025b6ae86d33610e03059093fcf 100644
--- a/ash/wm/root_window_layout_manager.cc
+++ b/ash/wm/root_window_layout_manager.cc
@@ -9,25 +9,20 @@
 #include "ui/aura/window_tracker.h"
 
 namespace ash {
-namespace wm {
-
-////////////////////////////////////////////////////////////////////////////////
-// RootWindowLayoutManager, public:
 
-RootWindowLayoutManager::RootWindowLayoutManager(WmWindow* owner)
-    : owner_(owner) {}
+namespace {
 
-RootWindowLayoutManager::~RootWindowLayoutManager() {}
-
-////////////////////////////////////////////////////////////////////////////////
-// RootWindowLayoutManager, aura::LayoutManager implementation:
-
-void RootWindowLayoutManager::OnWindowResized() {
-  const gfx::Rect fullscreen_bounds = gfx::Rect(owner_->GetBounds().size());
+void ResizeWindow(const aura::Window::Windows& children,
+                  const gfx::Rect& fullscreen_bounds,
+                  int depth) {
+  // Stop to prevent resizing non top level window such as tooltip.
+  if (depth > 2)
+    return;

[sadrul, 2017/04/14 05:52:44]

This doesn't make sense. Why not check to see if the Window actually is a
top-level window?

[oshima, 2017/04/14 06:52:15]

This is equivalent to what current code does. This layer manager is responsible
for specific containers, minus toplevel windows. Since
non container window can also have null delegate, it may
resize a window this layout manager isn't responsible for.

I agree that this can be improved but that's outside of the CL's scope.

[sadrul, 2017/04/14 17:00:58]

OK. I guess checking 'window->GetTopLevelWindow() == window' doesn't work? That
probably means the comment is wrong. Can that be updated?

[oshima, 2017/04/14 17:28:45]

You're righ. I'll talk to wutao and we'll update the comment.

For layer change, we'll address it in a separate CL.

[wutao, 2017/04/14 17:56:21]

Comments are updated.

 
   // Resize both our immediate children (the containers-of-containers animated
   // by PowerButtonController) and their children (the actual containers).
-  aura::WindowTracker children_tracker(owner_->aura_window()->children());
+  const int child_depth = depth + 1;
+  aura::WindowTracker children_tracker(children);
   while (!children_tracker.windows().empty()) {
     aura::Window* child = children_tracker.Pop();
     // Skip descendants of top-level windows, i.e. only resize containers and
@@ -36,15 +31,30 @@ void RootWindowLayoutManager::OnWindowResized() {
       continue;
 
     child->SetBounds(fullscreen_bounds);
-    aura::WindowTracker grandchildren_tracker(child->children());
-    while (!grandchildren_tracker.windows().empty()) {
-      child = grandchildren_tracker.Pop();
-      if (!child->GetToplevelWindow())
-        child->SetBounds(fullscreen_bounds);
-    }
+    ResizeWindow(child->children(), fullscreen_bounds, child_depth);
   }
 }
 
+}  // namespace
+
+namespace wm {
+
+////////////////////////////////////////////////////////////////////////////////
+// RootWindowLayoutManager, public:
+
+RootWindowLayoutManager::RootWindowLayoutManager(WmWindow* owner)
+    : owner_(owner) {}
+
+RootWindowLayoutManager::~RootWindowLayoutManager() {}
+
+////////////////////////////////////////////////////////////////////////////////
+// RootWindowLayoutManager, aura::LayoutManager implementation:
+
+void RootWindowLayoutManager::OnWindowResized() {
+  ResizeWindow(owner_->aura_window()->children(),
+               gfx::Rect(owner_->GetBounds().size()), 0);
+}
+
 void RootWindowLayoutManager::OnWindowAddedToLayout(WmWindow* child) {}
 
 void RootWindowLayoutManager::OnWillRemoveWindowFromLayout(WmWindow* child) {}