Don't compile code for desktop zoom or GuestViews on mobile platforms.

components/BUILD.gn

Index: components/BUILD.gn
diff --git a/components/BUILD.gn b/components/BUILD.gn
index 8f317aabd9f30d9247793d0479f3eea2517f1f6c..0e5a648dcfdb3e0f9dfbf4ae468182af3c9cf9c9 100644
--- a/components/BUILD.gn
+++ b/components/BUILD.gn
@@ -5,6 +5,7 @@
 import("//build/config/chrome_build.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
+import("//extensions/features/features.gni")
 import("//printing/features/features.gni")
 import("//rlz/features/features.gni")
 import("//testing/test.gni")
@@ -160,6 +161,10 @@ test("components_unittests") {
     deps += [ "//components/nacl/browser:unit_tests" ]
   }
 
+  if (enable_extensions) {
+    deps += [ "//components/guest_view/browser:unit_tests" ]
+  }
+
   if (is_ios) {
     deps += [
       "//components/image_fetcher/ios:unit_tests",
@@ -188,7 +193,6 @@ test("components_unittests") {
       "//components/error_page/renderer:unit_tests",
       "//components/favicon/content:unit_tests",
       "//components/gcm_driver/instance_id:unit_tests",
-      "//components/guest_view/browser:unit_tests",
       "//components/history/content/browser:unit_tests",
       "//components/invalidation/impl:unit_tests",
       "//components/keyed_service/content:unit_tests",
@@ -224,7 +228,6 @@ test("components_unittests") {
       "//components/wallpaper:unit_tests",
       "//components/web_cache/browser:unit_tests",
       "//components/webcrypto:unit_tests",
-      "//components/zoom:unit_tests",
     ]
 
     data_deps = [
@@ -280,6 +283,7 @@ test("components_unittests") {
       "//components/proximity_auth:unit_tests",
       "//components/storage_monitor:unit_tests",
       "//components/web_modal:unit_tests",
+      "//components/zoom:unit_tests",
     ]
   }