Fix browser_tests failure.

chrome/browser/chromeos/input_method/xkeyboard.cc

Index: chrome/browser/chromeos/input_method/xkeyboard.cc
diff --git a/chrome/browser/chromeos/input_method/xkeyboard.cc b/chrome/browser/chromeos/input_method/xkeyboard.cc
index fadb3f04822546cce7479775185495c27b15dccd..6ae6472cdc83ac820b954acf6b9cba5011f05c9a 100644
--- a/chrome/browser/chromeos/input_method/xkeyboard.cc
+++ b/chrome/browser/chromeos/input_method/xkeyboard.cc
@@ -283,14 +283,9 @@ unsigned int XKeyboardImpl::GetNumLockMask() {
 
 void XKeyboardImpl::GetLockedModifiers(bool* out_caps_lock_enabled,
                                        bool* out_num_lock_enabled) {
-  // For now, don't call CHECK() here to make
-  // TabRestoreServiceTest.DontRestorePrintPreviewTab test happy.
-  // TODO(yusukes): Fix the test, then fix the if(!BrowserThread...) line below.
-  // CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  if (!BrowserThread::CurrentlyOn(BrowserThread::UI) ||
-      (out_num_lock_enabled && !num_lock_mask_)) {
-    VLOG(1) << "Cannot get locked modifiers. Num Lock mask unknown.";
+  // The method might be called by browser_tests running on Linux.
+  if (!is_running_on_chrome_os_ || (out_num_lock_enabled && !num_lock_mask_)) {
+    VLOG(1) << "Cannot get locked modifiers.";
     if (out_caps_lock_enabled) {
       *out_caps_lock_enabled = false;
     }
@@ -300,6 +295,7 @@ void XKeyboardImpl::GetLockedModifiers(bool* out_caps_lock_enabled,
     return;
   }
 
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   XkbStateRec status;
   XkbGetState(ui::GetXDisplay(), XkbUseCoreKbd, &status);
   if (out_caps_lock_enabled) {