Move ViewHostMsg_CreateWindow to mojom

ui/base/BUILD.gn

Index: ui/base/BUILD.gn
diff --git a/ui/base/BUILD.gn b/ui/base/BUILD.gn
index fbf30d22f4845e7034b15f95dd9e5345d087ec73..e88e30fdcb29cef3fc8f401750b6b5fcf1ec1e34 100644
--- a/ui/base/BUILD.gn
+++ b/ui/base/BUILD.gn
@@ -6,6 +6,7 @@ import("//build/buildflag_header.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
+import("//mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 import("//ui/ozone/ozone.gni")
@@ -362,6 +363,7 @@ component("base") {
   defines = [ "UI_BASE_IMPLEMENTATION" ]
 
   public_deps = [
+    ":mojo_bindings",
     ":ui_data_pack",
     ":ui_features",
     "//base",
@@ -960,3 +962,9 @@ if (is_mac) {
     output_name = "ui_unittests Framework"
   }
 }
+
+mojom("mojo_bindings") {
+  sources = [
+    "window_open_disposition.mojom",
+  ]
+}