ChromeOS MD: Fix cannot drag tab onto immersive fullscreen window

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

 // Copyright 2012 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_view.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 134 matching lines @@
 #include "ui/views/widget/native_widget.h"
 #include "ui/views/widget/root_view.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/dialog_delegate.h"
 
 #if !defined(OS_CHROMEOS)
 #include "chrome/browser/ui/views/profiles/profile_chooser_view.h"
 #endif
 
 #if defined(USE_ASH)
+#include "ash/common/material_design/material_design_controller.h"
 #include "chrome/browser/ui/ash/ash_util.h"
 #endif
 
 #if defined(USE_AURA)
 #include "ui/aura/client/window_parenting_client.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #endif
 
 #if defined(OS_WIN)
@@ skipping 354 matching lines @@
   // The background image starts tiling horizontally at the window left edge and
   // vertically at the top edge of the horizontal tab strip (or where it would
   // be).  We expect our parent's origin to be the window origin.
   gfx::Point window_point(point + GetMirroredPosition().OffsetFromOrigin());
   window_point.Offset(frame_->GetThemeBackgroundXInset(),
                       -frame_->GetTopInset(false));
   return window_point;
 }
 
 bool BrowserView::IsTabStripVisible() const {
-  if (immersive_mode_controller_->ShouldHideTopViews() &&
-      immersive_mode_controller_->ShouldHideTabIndicators()) {
-    return false;
+  if (immersive_mode_controller_->ShouldHideTopViews()) {
+#if defined(USE_ASH)

[sky, 2017/02/01 16:31:37]

USE_ASH is now the same as OS_CHROMEOS and will eventually be replaced by it.
Please use OS_CHROMEOS in new code (as your touching includes above, please
merge the USE_ASH and OS_CHROMEOS sections.

[Qiang(Joe) Xu, 2017/02/01 18:58:09]

Done.

+    // For MD immersive fullscreen, tabstrip is considered as visible. Since top
+    // container is off screen, tapstrip is still invisible to user.
+    if (ash::MaterialDesignController::IsImmersiveModeMaterial())

[sky, 2017/02/01 16:31:37]

Does it really matter whether md or not? I'm wondering if we can remove the
branch (lines 530-539) entirely?

[Qiang(Joe) Xu, 2017/02/01 18:58:10]

done, and I find IsImmersiveModeMaterial is equivalent to
ShouldHideTabIndicators. So we can completely remote this trunk of lines.

+      return true;
+#endif
+    if (immersive_mode_controller_->ShouldHideTabIndicators())
+      return false;
   }
 
   // Return false if this window does not normally display a tabstrip.
   if (!browser_->SupportsWindowFeature(Browser::FEATURE_TABSTRIP))
     return false;
 
   // Return false if the tabstrip has not yet been created (by InitViews()),
   // since callers may otherwise try to access it. Note that we can't just check
   // this alone, as the tabstrip is created unconditionally even for windows
   // that won't display it.
@@ skipping 2101 matching lines @@
 }
 
 extensions::ActiveTabPermissionGranter*
 BrowserView::GetActiveTabPermissionGranter() {
   content::WebContents* web_contents = GetActiveWebContents();
   if (!web_contents)
     return nullptr;
   return extensions::TabHelper::FromWebContents(web_contents)
       ->active_tab_permission_granter();
 }