Restructure public side of window_manager service

services/view_manager/BUILD.gn

Index: services/view_manager/BUILD.gn
diff --git a/services/view_manager/BUILD.gn b/services/view_manager/BUILD.gn
index 847d7ad329fc44faf8843d52e0c87c5f9d64262f..ca21132b1b2d7823f61409252f87b3d1e9a04e67 100644
--- a/services/view_manager/BUILD.gn
+++ b/services/view_manager/BUILD.gn
@@ -20,7 +20,7 @@ mojo_native_application("view_manager") {
     "//mojo/environment:chromium",
     "//mojo/converters/geometry",
     "//mojo/public/cpp/bindings:bindings",
-    "//mojo/services/public/interfaces/window_manager",
+    "//mojo/services/window_manager/public/interfaces",
   ]
 }
 
@@ -71,8 +71,8 @@ source_set("view_manager_lib") {
     "//mojo/services/public/interfaces/native_viewport",
     "//mojo/services/public/interfaces/surfaces",
     "//mojo/services/public/interfaces/view_manager",
-    "//mojo/services/public/interfaces/window_manager",
     "//mojo/services/public/cpp/view_manager:common",
+    "//mojo/services/window_manager/public/interfaces",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
@@ -121,7 +121,7 @@ test("view_manager_service_unittests") {
     "//mojo/services/public/cpp/view_manager",
     "//mojo/services/public/interfaces/geometry",
     "//mojo/services/public/interfaces/view_manager",
-    "//mojo/services/public/interfaces/window_manager",
+    "//mojo/services/window_manager/public/interfaces",
     "//testing/gtest",
     "//ui/gfx",
     "//ui/gfx:test_support",
@@ -149,6 +149,6 @@ mojo_native_application("view_manager_service_apptests") {
     "//mojo/public/cpp/bindings",
     "//mojo/services/public/interfaces/geometry",
     "//mojo/services/public/interfaces/view_manager",
-    "//mojo/services/public/interfaces/window_manager",
+    "//mojo/services/window_manager/public/interfaces",
   ]
 }