lacros: don't set pangocairo

Fixes lld.elf: error: undefined symbol:
content::GetFontsInFamily_SlowBlocking.

R=fangzhoug, thomasanderson

Bug: 1121319
Change-Id: Idc9fec3ad300aa963ffc2ee1dfa626657906e86d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2374525Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Kramer Ge <fangzhoug@chromium.org>
Commit-Queue: Maksim Sisov (GMT+3) <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#801433}

build/config/linux/pangocairo/pangocairo.gni

@@ -2,8 +2,10 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/ui.gni")
 
 declare_args() {
-  use_pangocairo = is_linux && !is_chromeos && !is_chromecast
+  use_pangocairo =
+      is_linux && !is_chromeos && !is_chromecast && !chromeos_is_browser_only
 }