[lacros] Frameheaders should be drawn only if custom-frame is enabled

When toplevel window uses a native frame, the server-side decoration is
set and when toplevel window uses a custom frame, the client-side
decoration is set. UseCustomFrame() decides on which frame (native or
custom) to be used for a window.

Devtool chooses a native frame but also draws frame header
(client-side decoration) causing a duplicate decoration for a devtool
window.

BrowserFrame::ShouldDrawFrameHeader always returns `true` assuming
that custom frame is used but instead, this function should check frame
type before drawing a frame header.

Bug: 1155551
Change-Id: I903a194ecf875f51d5ade726b57651c57bd7b028
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2573711Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Abhijeet Kandalkar <abhijeet@igalia.com>
Cr-Commit-Position: refs/heads/master@{#836680}

chrome/browser/ui/BUILD.gn

@@ -2766,6 +2766,8 @@ static_library("ui") {
     sources += [
       "views/chrome_browser_main_extra_parts_views_lacros.cc",
       "views/chrome_browser_main_extra_parts_views_lacros.h",
+      "views/frame/browser_frame_lacros.cc",
+      "views/frame/browser_frame_lacros.h",
       "views/frame/immersive_mode_controller_chromeos.cc",
       "views/frame/immersive_mode_controller_chromeos.h",
       "window_sizer/window_sizer_chromeos.cc",

chrome/browser/ui/views/frame/OWNERS

@@ -4,6 +4,7 @@ sky@chromium.org
 
 per-file *_ash*=jamescook@chromium.org
 per-file *_chromeos*=jamescook@chromium.org
+per-file *_lacros*=jamescook@chromium.org
 per-file *x11*=thomasanderson@chromium.org
 per-file desktop_linux_browser_frame_view*=thomasanderson@chromium.org
 per-file immersive_mode_controller*=pkotwicz@chromium.org

chrome/browser/ui/views/frame/browser_frame_lacros.cc

+// Copyright 2020 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 "chrome/browser/ui/views/frame/browser_frame_lacros.h"
+
+BrowserFrameLacros::BrowserFrameLacros(BrowserView* browser_view)
+    : BrowserFrame(browser_view) {}
+
+// In Lacros, windows that use 'custom frame' should draw their own
+// frame header (ie client-side window decoration). This is the case of
+// the lacros/chrome browser windows, for instance.
+// On the other hand, windows like devtools do not use a "custom frame"
+// and hence defer its frame header drawing to the host WindowManager
+// (ie server-side window decoration).
+bool BrowserFrameLacros::ShouldDrawFrameHeader() const {
+  return UseCustomFrame();
+}

chrome/browser/ui/views/frame/browser_frame_lacros.h

+// Copyright 2020 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.
+
+#ifndef CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_FRAME_LACROS_H_
+#define CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_FRAME_LACROS_H_
+
+#include "chrome/browser/ui/views/frame/browser_frame.h"
+
+class BrowserView;
+
+// BrowserFrameLacros provides the frame for Lacros browser windows.
+class BrowserFrameLacros : public BrowserFrame {
+ public:
+  explicit BrowserFrameLacros(BrowserView* browser_view);
+
+  // BrowserFrame
+  bool ShouldDrawFrameHeader() const override;
+
+ protected:
+  ~BrowserFrameLacros() override = default;
+};
+
+#endif  // CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_FRAME_LACROS_H_

chrome/browser/ui/views/frame/browser_window_factory.cc

@@ -9,6 +9,9 @@
 #if BUILDFLAG(IS_CHROMEOS_ASH)
 #include "chrome/browser/ui/views/frame/custom_tab_browser_frame.h"
 #endif
+#if BUILDFLAG(IS_CHROMEOS_LACROS)
+#include "chrome/browser/ui/views/frame/browser_frame_lacros.h"
+#endif
 #include "chrome/browser/ui/views/frame/native_browser_frame_factory.h"
 #include "chrome/grit/chromium_strings.h"
 #include "components/safe_browsing/core/password_protection/metrics_util.h"
@@ -32,6 +35,9 @@ BrowserWindow* BrowserWindow::CreateBrowserWindow(
 #if BUILDFLAG(IS_CHROMEOS_ASH)
   if (view->browser()->is_type_custom_tab())
     browser_frame = new CustomTabBrowserFrame(view);
+#endif
+#if BUILDFLAG(IS_CHROMEOS_LACROS)
+  browser_frame = new BrowserFrameLacros(view);
 #endif
   if (!browser_frame)
     browser_frame = new BrowserFrame(view);