Lacros: Preparation for lacros target_os switch.

This is a mechanical change replacing defined(OS_CHROMEOS) with
BUILDFLAG(IS_CHROMEOS_ASH) to ensure that switching lacros' target_os
from linux to chromeos will not affect the lacros binary.

More detail on http://go/lacros-macros.

Bug: 1052397
Change-Id: Id4b8f4ea0605a897cadbf2140201e2b8efe7acd6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2627653Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Yuta Hijikata <ythjkt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843873}

ui/views/BUILD.gn

@@ -531,7 +531,7 @@ component("views") {
     deps += [ "//ui/display/util" ]
   }
 
-  if (is_chromeos) {
+  if (is_chromeos_ash) {
     deps += [ "//ui/base/ime/chromeos" ]
   }
 

ui/views/controls/textfield/textfield.cc

@@ -96,7 +96,7 @@
 #include "ui/ozone/public/platform_gl_egl_utility.h"
 #endif
 
-#if defined(OS_CHROMEOS)
+#if BUILDFLAG(IS_CHROMEOS_ASH)
 #include "ui/base/ime/chromeos/extension_ime_util.h"
 #include "ui/base/ime/chromeos/input_method_manager.h"
 #endif
@@ -1943,7 +1943,7 @@ bool Textfield::SetAutocorrectRange(const gfx::Range& range) {
     base::UmaHistogramEnumeration("InputMethod.Assistive.Autocorrect.Count",
                                   TextInputClient::SubClass::kTextField);
 
-#if defined(OS_CHROMEOS)
+#if BUILDFLAG(IS_CHROMEOS_ASH)
     auto* input_method_manager =
         chromeos::input_method::InputMethodManager::Get();
     if (input_method_manager &&

ui/views/controls/views_text_services_context_menu_base.h

@@ -6,6 +6,7 @@
 #define UI_VIEWS_CONTROLS_VIEWS_TEXT_SERVICES_CONTEXT_MENU_BASE_H_
 
 #include "build/build_config.h"
+#include "build/chromeos_buildflags.h"
 #include "ui/views/controls/views_text_services_context_menu.h"
 #include "ui/views/views_export.h"
 
@@ -33,7 +34,7 @@ class VIEWS_EXPORT ViewsTextServicesContextMenuBase
   bool SupportsCommand(int command_id) const override;
 
  protected:
-#if defined(OS_APPLE) || defined(OS_CHROMEOS)
+#if defined(OS_APPLE) || BUILDFLAG(IS_CHROMEOS_ASH)
   Textfield* client() { return client_; }
   const Textfield* client() const { return client_; }
 #endif

ui/webui/resources/BUILD.gn

@@ -27,7 +27,7 @@ generate_grd("build_grd") {
     "$target_gen_dir/js/resources.grdp",
   ]
 
-  if (!is_chromeos && !is_android) {
+  if (!is_chromeos_ash && !is_android) {
     # Roboto Font. Roboto-Regular and Roboto-Light is already available on
     # Android, and Roboto-Medium is not used on Android. All 6 weights of
     # Roboto are available on Chrome OS.