Decompose //extensions/browser/BUILD.gn

extensions/browser/mojo/BUILD.gn

Index: extensions/browser/mojo/BUILD.gn
diff --git a/services/catalog/public/cpp/BUILD.gn b/extensions/browser/mojo/BUILD.gn
similarity index 52%
copy from services/catalog/public/cpp/BUILD.gn
copy to extensions/browser/mojo/BUILD.gn
index 3b2def13e7e2d22f958a5a54913022f3dab96347..dde44d2dfc2997af42c2a77d16ac92059b9fedd8 100644
--- a/services/catalog/public/cpp/BUILD.gn
+++ b/extensions/browser/mojo/BUILD.gn
@@ -2,17 +2,18 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("cpp") {
+source_set("mojo") {
   sources = [
-    "resource_loader.cc",
-    "resource_loader.h",
+    "keep_alive_impl.cc",
+    "keep_alive_impl.h",
+    "service_registration.cc",
+    "service_registration.h",
+    "stash_backend.cc",
+    "stash_backend.h",
   ]
 
   deps = [
-    "//base",
-    "//components/filesystem/public/interfaces",
-    "//mojo/public/cpp/bindings",
-    "//mojo/public/cpp/system",
+    "//extensions/common:mojo",
     "//services/shell/public/cpp",
   ]
 }