Add FrameHost mojo service

content/common/frame_host.mojom

Index: content/common/frame_host.mojom
diff --git a/components/autofill/content/public/interfaces/autofill_driver.mojom b/content/common/frame_host.mojom
similarity index 55%
copy from components/autofill/content/public/interfaces/autofill_driver.mojom
copy to content/common/frame_host.mojom
index 3724043db4083fc126c8da79ecf263edac38c8c2..01554a05d2ea2daf92dc6bf9e1f36e2afa92213e 100644
--- a/components/autofill/content/public/interfaces/autofill_driver.mojom
+++ b/content/common/frame_host.mojom
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-module autofill.mojom;
+module content.mojom;
 
-interface AutofillDriver {
-  // Notification that there has been a user gesture.
-  FirstUserGestureObserved();
+import "url/mojo/url.mojom";
+
+interface FrameHost {
+  GetHostZoomLevel(url.mojom.Url url) => (double zoom_level);
 };