mash: Don't draw the window title under chrome tabs.

mash/wm/non_client_frame_controller.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mash/wm/non_client_frame_controller.h"
 
 #include <stdint.h>
 
 #include <memory>
 
@@ skipping 238 matching lines @@
          (GetResizeBehavior(window_) &
           mus::mojom::kResizeBehaviorCanMaximize) != 0;
 }
 
 bool NonClientFrameController::CanMinimize() const {
   return window_ &&
          (GetResizeBehavior(window_) &
           mus::mojom::kResizeBehaviorCanMinimize) != 0;
 }
 
+bool NonClientFrameController::ShouldShowWindowTitle() const {
+  // Only draw the title if the client hasn't declared any additional client
+  // areas which might conflict with it.
+  return window_ && window_->additional_client_areas().empty();
+}
+
 views::ClientView* NonClientFrameController::CreateClientView(
     views::Widget* widget) {
   return new ClientViewMus(widget, GetContentsView(), this);
 }
 
 void NonClientFrameController::OnWindowSharedPropertyChanged(
     mus::Window* window,
     const std::string& name,
     const std::vector<uint8_t>* old_data,
     const std::vector<uint8_t>* new_data) {
   if (name == mus::mojom::WindowManager::kResizeBehavior_Property)
     widget_->OnSizeConstraintsChanged();
   else if (name == mus::mojom::WindowManager::kWindowTitle_Property)
     widget_->UpdateWindowTitle();
 }
 
 void NonClientFrameController::OnWindowDestroyed(mus::Window* window) {
   window_->RemoveObserver(this);
   window_ = nullptr;
 }
 
 }  // namespace wm
 }  // namespace mash