Stop suppressing -Wtautological-bitwise-compare.

Except on Chrome OS for now,
https://chromium-review.googlesource.com/c/chromium/src/+/1306406/23/components/exo/wayland/zwp_text_input_manager.cc#123

Bug: 1024203
Change-Id: I05995c4565e34f46c3f8cdb32a8cc3ab46ff17b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1937652
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Reid Kleckner <rnk@chromium.org>
Auto-Submit: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719638}

build/config/compiler/BUILD.gn

@@ -1532,9 +1532,6 @@ config("default_warnings") {
 
           # TODO(https://crbug.com/1016945) Clean up, enable.
           "-Wno-builtin-assume-aligned-alignment",
-
-          # TODO(https://crbug.com/1024203) Clean up, enable.
-          "-Wno-tautological-bitwise-compare",
         ]
 
         if (is_fuchsia || is_mac) {
@@ -1543,6 +1540,12 @@ config("default_warnings") {
             "-Wno-c99-designator",
           ]
         }
+        if (is_chromeos) {
+          cflags += [
+            # TODO(https://crbug.com/1024203): Clean up, enable.
+            "-Wno-tautological-bitwise-compare",
+          ]
+        }
         if (is_win) {
           cflags += [
             # TODO(https://crbug.com/1002945): Clean up, enable.