Apply new MD shadows to CrOS tray bubbles.

ui/wm/core/shadow_controller.cc

Index: ui/wm/core/shadow_controller.cc
diff --git a/ui/wm/core/shadow_controller.cc b/ui/wm/core/shadow_controller.cc
index 48004100f6aa146cb6603f50e25ba6c8d51cdbbb..ce30bbdabc8f504929fca934eefd2919ef413d95 100644
--- a/ui/wm/core/shadow_controller.cc
+++ b/ui/wm/core/shadow_controller.cc
@@ -45,20 +45,22 @@ ShadowType GetShadowTypeFromWindow(aura::Window* window) {
   return SHADOW_TYPE_NONE;
 }
 
-bool ShouldUseSmallShadowForWindow(aura::Window* window) {
+Shadow::Style GetShadowStyleForWindow(aura::Window* window) {
   switch (window->type()) {
     case ui::wm::WINDOW_TYPE_MENU:
     case ui::wm::WINDOW_TYPE_TOOLTIP:
-      return true;
+      return Shadow::STYLE_SMALL;
+
+    // System tray bubbles render like active windows. TODO(estade): this
+    // mechanism will need to be revisited for applying WM shadows to other
+    // types of bubbles which don't want to render such large shadows.
+    case ui::wm::WINDOW_TYPE_POPUP:
+      return Shadow::STYLE_ACTIVE;

[James Cook, 2016/12/10 00:19:16]

This still concerns me. You're relying on the fact that no one happens to turn
on shadows for popup windows right now.

How does the code work today? Visually in ToT it looks to me like system tray
bubbles have the same big shadows as active windows.

[Evan Stade, 2016/12/12 17:51:20]

I don't think that's an unreasonable assumption. It wouldn't make sense to just
flip them on for popups with or without this patch. You're right, we need to
eventually address it (as per the TODO), but as a part of future work.
yes, that is accurate. Spec[1]. This is category 5 (it's ambiguous whether that
applies to just the system menu or all tray bubbles but I assume the latter as
interaction patterns are the same), and it matches category 1 (active
application frame).

[1]
https://folio.googleplex.com/andromeda/Chrome%20OS/System%20Components/Specs%...

[James Cook, 2016/12/12 18:33:07]

I meant, how does the code work today to paint the system tray bubbles with
large shadows? Apparently they are not active, otherwise you wouldn't need this
line and could rely on 61 below.

[sky, 2016/12/12 19:16:53]

Bubbles are mapped to ui::wm::WINDOW_TYPE_POPUP, which by default shouldn't have
a shadow. Is someone explicitly calling SetShadowType()?

[Evan Stade, 2016/12/12 21:28:40]

They don't get wm shadows at all currently. With this patch they do because of
changes in TrayBubbleView.

+
     default:
-      break;
+      return IsActiveWindow(window) ? Shadow::STYLE_ACTIVE
+                                    : Shadow::STYLE_INACTIVE;
   }
-  return false;
-}
-
-Shadow::Style GetShadowStyleForWindow(aura::Window* window) {
-  return ShouldUseSmallShadowForWindow(window) ? Shadow::STYLE_SMALL :
-      (IsActiveWindow(window) ? Shadow::STYLE_ACTIVE : Shadow::STYLE_INACTIVE);
 }
 
 // Returns the shadow style to be applied to |losing_active| when it is losing
@@ -193,12 +195,13 @@ void ShadowController::Impl::OnWindowActivated(ActivationReason reason,
                                                aura::Window* lost_active) {
   if (gained_active) {
     Shadow* shadow = GetShadowForWindow(gained_active);
-    if (shadow && !ShouldUseSmallShadowForWindow(gained_active))
-      shadow->SetStyle(Shadow::STYLE_ACTIVE);
+    if (shadow)
+      shadow->SetStyle(GetShadowStyleForWindow(gained_active));
   }
   if (lost_active) {
     Shadow* shadow = GetShadowForWindow(lost_active);
-    if (shadow && !ShouldUseSmallShadowForWindow(lost_active)) {
+    if (shadow &&
+        GetShadowStyleForWindow(lost_active) == Shadow::STYLE_INACTIVE) {
       shadow->SetStyle(GetShadowStyleForWindowLosingActive(lost_active,
                                                            gained_active));
     }