Let Chrome app handle Ash accelerators first if the app is launched as a window

ash/accelerators/accelerator_filter.cc

Index: ash/accelerators/accelerator_filter.cc
diff --git a/ash/accelerators/accelerator_filter.cc b/ash/accelerators/accelerator_filter.cc
index dcc95ba9bd9c037f56383601b29a4ffb724b0278..0a799b1eba39dc59f4902dad0277b96adb2b0ad9 100644
--- a/ash/accelerators/accelerator_filter.cc
+++ b/ash/accelerators/accelerator_filter.cc
@@ -6,15 +6,41 @@
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/shell.h"
+#include "ash/shell_delegate.h"
+#include "ash/wm/window_util.h"
+#include "ui/aura/client/aura_constants.h"
+#include "ui/aura/client/window_types.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/base/accelerators/accelerator_manager.h"
+#include "ui/base/ui_base_types.h"
 
 namespace {
+
 const int kModifierFlagMask = (ui::EF_SHIFT_DOWN |
                                ui::EF_CONTROL_DOWN |
                                ui::EF_ALT_DOWN);
+
+// Returns true if an Ash accelerator should be processed now.
+bool ShouldProcessAcceleratorsNow(aura::Window* target) {
+  if (!target)
+    return true;
+
+  // Check obvious cases before going to the slow path.
+  if (target->type() != aura::client::WINDOW_TYPE_UNKNOWN &&
+      target->type() != aura::client::WINDOW_TYPE_NORMAL) {
+    return true;
+  }
+  if (target == ash::Shell::GetRootWindow())
+    return true;
+
+  ash::ShellDelegate* delegate = ash::Shell::GetInstance()->delegate();
+  if (!delegate)
+    return true;
+  return !delegate->IsBrowserWindow(ash::wm::GetActivatableWindow(target));
+}
+
 }  // namespace
 
 namespace ash {
@@ -40,6 +66,11 @@ bool AcceleratorFilter::PreHandleKeyEvent(aura::Window* target,
   if (event->is_char())
     return false;
 
+  // When a browser or app window is focused, don't process Ash global
+  // shortcuts here so the app could check it first. crbug.com/123856
+  if (!ShouldProcessAcceleratorsNow(target))
+    return false;
+
   ui::Accelerator accelerator(event->key_code(),
                               event->flags() & kModifierFlagMask);
   accelerator.set_type(type);