Fix gtk3 build

remoting/host/it2me/BUILD.gn

Index: remoting/host/it2me/BUILD.gn
diff --git a/remoting/host/it2me/BUILD.gn b/remoting/host/it2me/BUILD.gn
index c86ff54228f14c30c19ce235976a6ec80c3efa06..5427ca556fb1b3270aebc3c163dd9841dcc040c1 100644
--- a/remoting/host/it2me/BUILD.gn
+++ b/remoting/host/it2me/BUILD.gn
@@ -66,7 +66,11 @@ source_set("common") {
     # See crbug.com/462689 for details.
     all_dependent_configs = [ "//third_party/harfbuzz-ng:pangoft2_link_hack" ]
 
-    deps += [ "//build/config/linux/gtk2" ]
+    if (use_gtk3) {
+      deps += [ "//build/config/linux/gtk3" ]
+    } else {
+      deps += [ "//build/config/linux/gtk2" ]
+    }
   }
 }
 
@@ -230,7 +234,11 @@ if (!is_chromeos && !is_android && enable_remoting_host) {
       }
 
       if (is_desktop_linux) {
-        deps += [ "//build/config/linux/gtk2" ]
+        if (use_gtk3) {
+          deps += [ "//build/config/linux/gtk3" ]
+        } else {
+          deps += [ "//build/config/linux/gtk2" ]
+        }
       }
     }
   }