Rename is_chromeos in chrome/src.

chrome/BUILD.gn

Index: chrome/BUILD.gn
diff --git a/chrome/BUILD.gn b/chrome/BUILD.gn
index c71641b0bede306ac08743a2713f136f34e1904b..77408c43e89a0349b554427431658827b27c4deb 100644
--- a/chrome/BUILD.gn
+++ b/chrome/BUILD.gn
@@ -441,7 +441,7 @@ group("extra_resources") {
     ]
   }
 
-  if (is_chromeos) {
+  if (is_chromeos_ui) {
     deps += [ "//chrome/browser/resources/chromeos/chromevox" ]
   }
 
@@ -560,7 +560,7 @@ repack("packed_extra_resources") {
       "//third_party/WebKit/public:resources",
     ]
   }
-  if (is_chromeos) {
+  if (is_chromeos_ui) {
     sources += [ "$root_gen_dir/ui/file_manager/file_manager_resources.pak" ]
     deps += [ "//ui/file_manager:resources" ]
   }
@@ -684,7 +684,7 @@ template("chrome_repack_percent") {
       sources += [ "$root_gen_dir/ui/views/resources/views_resources_${percent}_percent.pak" ]
       deps += [ "//ui/views/resources" ]
     }
-    if (is_chromeos) {
+    if (is_chromeos_ui) {
       sources += [ "$root_gen_dir/ui/chromeos/resources/ui_chromeos_resources_${percent}_percent.pak" ]
       deps += [ "//ui/chromeos/resources" ]
     }