Temporarily sets always-on-top property to off when another window is fullscreen

A chrome app window with always-on-top property (e.g. Hangouts app) stays on top of even the fullscreen window (e.g. a video playing on full screen) and it would be better to temporarily clear the always-on-top property while another window is in fullscreen mode.
We already track fullscreen mode in Chrome OS and we already have a concept of temporarily clearing always-on-top property when that very window enters fullscreen state. This CL wires those together so that always-on-top windows are pushed below a fullscreen window and reassert their always-on-top property when workspace is no longer in fullscreen state.
This only applies to Chrome OS, Windows case may be more difficult to get right.

BUG=450055

Review URL: https://codereview.chromium.org/1180673012

Cr-Commit-Position: refs/heads/master@{#336663}

2 files changed, 10 insertions, 4 deletions

diff --git a/extensions/browser/app_window/app_window.cc b/extensions/browser/app_window/app_window.cc
index 4ebc38e..5a40efd 100644
--- a/extensions/browser/app_window/app_window.cc
+++ b/extensions/browser/app_window/app_window.cc
@@ -472,8 +472,7 @@ void AppWindow::OnNativeWindowChanged() {
     fullscreen_types_ = FULLSCREEN_TYPE_NONE;
   }
 
-  if (cached_always_on_top_)
-    UpdateNativeAlwaysOnTop();  // Same as in SetNativeWindowFullscreen.
+  RestoreAlwaysOnTop();  // Same as in SetNativeWindowFullscreen.
 #endif
 
   SaveWindowPosition();
@@ -703,6 +702,11 @@ void AppWindow::SetAlwaysOnTop(bool always_on_top) {
 
 bool AppWindow::IsAlwaysOnTop() const { return cached_always_on_top_; }
 
+void AppWindow::RestoreAlwaysOnTop() {
+  if (cached_always_on_top_)
+    UpdateNativeAlwaysOnTop();
+}
+
 void AppWindow::SetInterceptAllKeys(bool want_all_keys) {
   native_app_window_->SetInterceptAllKeys(want_all_keys);
 }
@@ -815,8 +819,7 @@ void AppWindow::UpdateExtensionAppIcon() {
 void AppWindow::SetNativeWindowFullscreen() {
   native_app_window_->SetFullscreen(fullscreen_types_);
 
-  if (cached_always_on_top_)
-    UpdateNativeAlwaysOnTop();
+  RestoreAlwaysOnTop();
 }
 
 bool AppWindow::IntersectsWithTaskbar() const {
diff --git a/extensions/browser/app_window/app_window.h b/extensions/browser/app_window/app_window.h
index 10267f6..12eb78d 100644
--- a/extensions/browser/app_window/app_window.h
+++ b/extensions/browser/app_window/app_window.h
@@ -327,6 +327,9 @@ class AppWindow : public content::WebContentsDelegate,
   // may be false if the bit is silently switched off for security reasons.
   bool IsAlwaysOnTop() const;
 
+  // Restores the always-on-top property according to |cached_always_on_top_|.
+  void RestoreAlwaysOnTop();
+
   // Set whether the window should get even reserved keys (modulo platform
   // restrictions).
   void SetInterceptAllKeys(bool want_all_keys);