Move mojo/application/public -> mojo/shell/public

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 205e74c388f33c8524018eead24864253efa9546..741ae414295b59c909c7deedf062ab756fbf0810 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -175,8 +175,8 @@ group("both_gn_and_gyp") {
       "//media/cast:cast_unittests",
       "//media/midi:midi_unittests",
       "//mojo",
-      "//mojo/application/public/cpp",
       "//mojo/common:mojo_common_unittests",
+      "//mojo/shell/public/cpp",
       "//net:net_perftests",
 
       # TODO(use-new-edk):
@@ -505,7 +505,7 @@ group("both_gn_and_gyp") {
       # TODO(GYP): Remove this when the gles2 tests work
       "//gpu/command_buffer/client:gles2_implementation_no_check",
       "//gpu/khronos_glcts_support:khronos_glcts_test",  # TODO(GYP) crbug.com/471903 to make this complete.
-      "//mojo/application/public/cpp",
+      "//mojo/shell/public/cpp",
       "//testing/gmock:gmock_main",
 
       # TODO(use-new-edk):