Reland "Reland "Enable ATK and Glib on Linux/Ozone""

This is a reland of 388f1d99

Original change's description:
> Reland "Enable ATK and Glib on Linux/Ozone"
>
> This is a reland of 16c153e6
>
> Original change's description:
> > Enable ATK and Glib on Linux/Ozone
> >
> > BUG=988094,1014934
> > R=sky
> > CC=nickdiego,msisov,adunaev
> >
> > Change-Id: I05b4bae5ccce53053ad4ae8269db849c2db9e569
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2056570
> > Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
> > Reviewed-by: Nick Yamane <nickdiego@igalia.com>
> > Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#742233}
>
> TBR=sadrul,jamiewalch
>
> Bug: 988094, 1014934
> Change-Id: Ide8b89767eddbdd6e6751db58c92d64e2d756fec
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2062911
> Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
> Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
> Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#742315}

R=sadrul
CQ_INCLUDE_TRYBOTS=luci.chromium.try:linux_chromium_archive_rel_ng

Bug: 988094, 1014934
Change-Id: I48b857751cfa3a1beaaf0555dcdba495dcde8670
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2063729
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#744382}

build/config/ui.gni

@@ -21,8 +21,7 @@ import("//build/config/chromecast_build.gni")
 
 declare_args() {
   # Indicates if Ozone is enabled. Ozone is a low-level library layer for Linux
-  # that does not require X11. Enabling this feature disables use of glib, x11,
-  # Pango, and Cairo.
+  # that does not require X11. Enabling this feature disables use of x11.
   use_ozone = is_chromeos || (is_chromecast && !is_android) || is_fuchsia
 
   # Indicates if Aura is enabled. Aura is a low-level windowing library, sort
@@ -35,7 +34,7 @@ declare_args() {
   toolkit_views = is_mac || is_win || is_linux || (is_fuchsia && is_chromecast)
 
   # Whether we should use glib, a low level C utility library.
-  use_glib = is_linux && !use_ozone
+  use_glib = is_desktop_linux && !is_chromecast
 }
 
 # Additional dependent variables -----------------------------------------------
@@ -49,7 +48,7 @@ use_x11 = is_linux && !use_ozone
 assert(!use_glib || (is_linux && !is_chromeos && !is_chromecast))
 
 # Whether to use atk, the Accessibility ToolKit library
-use_atk = is_desktop_linux && use_x11
+use_atk = is_desktop_linux && !is_chromecast
 # =============================================
 #   PLEASE DO NOT ADD MORE FLAGS TO THIS FILE
 # =============================================

ui/accessibility/platform/atk_util_auralinux.cc

@@ -145,11 +145,4 @@ DiscardAtkKeyEvent AtkUtilAuraLinux::HandleAtkKeyEvent(
   return discard ? DiscardAtkKeyEvent::Discard : DiscardAtkKeyEvent::Retain;
 }
 
-#if !defined(USE_X11)
-DiscardAtkKeyEvent AtkUtilAuraLinux::HandleKeyEvent(
-    const ui::KeyEvent& ui_key_event) {
-  NOTREACHED();
-}
-#endif
-
 }  // namespace ui

ui/gfx/native_widget_types.h

@@ -102,7 +102,7 @@ class ViewAndroid;
 #endif
 class SkBitmap;
 
-#if defined(USE_X11)
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
 extern "C" {
 struct _AtkObject;
 typedef struct _AtkObject AtkObject;
@@ -203,16 +203,15 @@ typedef id NativeViewAccessible;
 #elif defined(OS_MACOSX)
 typedef NSFont* NativeFont;
 typedef id NativeViewAccessible;
-#else  // Android, Linux, Chrome OS, etc.
+#elif defined(OS_LINUX) && !defined(OS_CHROMEOS)
 // Linux doesn't have a native font type.
-#if defined(USE_X11)
 typedef AtkObject* NativeViewAccessible;
 #else
+// Android, Chrome OS, etc.
 typedef struct _UnimplementedNativeViewAccessible
     UnimplementedNativeViewAccessible;
 typedef UnimplementedNativeViewAccessible* NativeViewAccessible;
 #endif
-#endif
 
 // A constant value to indicate that gfx::NativeCursor refers to no cursor.
 #if defined(USE_AURA)

ui/views/BUILD.gn

@@ -772,13 +772,6 @@ jumbo_component("views") {
           "widget/desktop_aura/x11_topmost_window_finder.cc",
           "widget/desktop_aura/x11_whole_screen_move_loop.cc",
         ]
-        if (use_atk) {
-          sources += [
-            "accessibility/view_ax_platform_node_delegate_auralinux.cc",
-            "accessibility/view_ax_platform_node_delegate_auralinux.h",
-          ]
-          configs += [ "//build/config/linux/atk" ]
-        }
       } else if (is_win) {
         public += [ "widget/desktop_aura/desktop_window_tree_host_win.h" ]
         sources += [
@@ -816,6 +809,13 @@ jumbo_component("views") {
             [ "widget/desktop_aura/desktop_window_tree_host_platform.cc" ]
         deps += [ "//ui/platform_window/extensions" ]
       }
+      if (use_atk) {
+        sources += [
+          "accessibility/view_ax_platform_node_delegate_auralinux.cc",
+          "accessibility/view_ax_platform_node_delegate_auralinux.h",
+        ]
+        configs += [ "//build/config/linux/atk" ]
+      }
     }
   }