Build //ui/keyboard/* only on Chrome OS.

Code under ui/keyboard should be used only on Chrome OS.
This CL stop s keyboard_unittests from running on non Chrome OS buildbots.

Bug: 847109
Test: trybots

Change-Id: I75d8c34d0ba575d45ac7bf981a167b469755ed90
Reviewed-on: https://chromium-review.googlesource.com/1006742
Commit-Queue: Yuichiro Hanada <[email protected]>
Reviewed-by: Michael Wasserman <[email protected]>
Reviewed-by: Shu Chen <[email protected]>
Reviewed-by: Devlin <[email protected]>
Reviewed-by: Dirk Pranke <[email protected]>
Cr-Commit-Position: refs/heads/master@{#566375}
diff --git a/chrome/browser/extensions/BUILD.gn b/chrome/browser/extensions/BUILD.gn
index fc0908e..928eb1b 100644
--- a/chrome/browser/extensions/BUILD.gn
+++ b/chrome/browser/extensions/BUILD.gn
@@ -1010,6 +1010,8 @@
       "//ui/chromeos",
       "//ui/chromeos/events",
       "//ui/file_manager",
+      "//ui/keyboard",
+      "//ui/keyboard:resources",
       "//ui/ozone",
       "//ui/views",
     ]
@@ -1148,11 +1150,7 @@
   }
 
   if (use_aura) {
-    deps += [
-      "//ui/aura",
-      "//ui/keyboard",
-      "//ui/keyboard:resources",
-    ]
+    deps += [ "//ui/aura" ]
   }
 
   if (use_brlapi) {