GN: Mojo wget, sample_app, surfaces app and component build

mojo/mojo_examples.gypi

Index: mojo/mojo_examples.gypi
diff --git a/mojo/mojo_examples.gypi b/mojo/mojo_examples.gypi
index 81b0a4fc4ab29e0dcb9503205f3995002696aafe..bd8b030b51ca292e97b2eb82ca495c39ed4523d1 100644
--- a/mojo/mojo_examples.gypi
+++ b/mojo/mojo_examples.gypi
@@ -5,6 +5,7 @@
 {
   'targets': [
     {
+      # GN version: //mojo/examples/echo:client
       'target_name': 'mojo_echo_client',
       'type': 'loadable_module',
       'dependencies': [
@@ -28,6 +29,7 @@
       'includes': [ 'build/package_app.gypi' ],
     },
     {
+      # GN version: //mojo/examples/echo:bindings
       'target_name': 'mojo_echo_service_bindings',
       'type': 'static_library',
       'sources': [
@@ -42,6 +44,7 @@
       ],
     },
     {
+      # GN version: //mojo/examples/echo:service
       'target_name': 'mojo_echo_service',
       'type': 'loadable_module',
       'dependencies': [
@@ -65,12 +68,10 @@
       'includes': [ 'build/package_app.gypi' ],
     },
     {
+      # GN version: //mojo/examples/sample_app
       'target_name': 'mojo_sample_app',
       'type': 'loadable_module',
       'dependencies': [
-        # TODO(darin): we should not be linking against these libraries!
-        '../ui/events/events.gyp:events',
-        '../ui/gfx/gfx.gyp:gfx_geometry',
         'mojo_base.gyp:mojo_application_standalone',
         'mojo_base.gyp:mojo_cpp_bindings',
         'mojo_base.gyp:mojo_environment_standalone',
@@ -189,6 +190,7 @@
       'includes': [ 'build/package_app.gypi' ],
     },
     {
+      # GN version: //mojo/examples/wget
       'target_name': 'mojo_wget',
       'type': 'loadable_module',
       'dependencies': [