[ios Mojo] iOS facade class for Mojo API.

ios/web/ios_web.gyp

Index: ios/web/ios_web.gyp
diff --git a/ios/web/ios_web.gyp b/ios/web/ios_web.gyp
index 2882d8cfc44a9a434281b3569bdacaac7934ae8d..e6b5ad74d32ebf95aae18b9ebf332ba0296f85a9 100644
--- a/ios/web/ios_web.gyp
+++ b/ios/web/ios_web.gyp
@@ -51,6 +51,9 @@
         '../../ios/net/ios_net.gyp:ios_net',
         '../../ios/third_party/blink/blink_html_tokenizer.gyp:blink_html_tokenizer',
         '../../net/net.gyp:net',
+        '../../mojo/mojo_edk.gyp:mojo_system_impl',
+        '../../mojo/mojo_public.gyp:mojo_public',
+        '../../services/shell/shell.gyp:shell_public',

[Eugene But (OOO till 7-30), 2016/05/07 00:07:52]

This creates a cycle in file dependencies, because filesystem.gyp uses
shell.gyp. GYP throws an exception when it detects file cycles (at least on
iOS):
https://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/build...

The cycle was created this CL:
https://codereview.chromium.org/1942473002/diff/320001/services/shell/shell.gyp

Maybe I should not pull shell.gyp:shell_public? This works on other platforms
though...

[Ken Rockot(use gerrit already), 2016/05/09 15:44:37]

Lame gyp behavior. There isn't really an interesting circular dependency (i.e.
among actual targets), just one among gyp files. Easiest solution would be to
move shell_public (and shell_interfaces) to a separate shell_public.gyp.

[Eugene But (OOO till 7-30), 2016/05/12 20:48:10]

This is now fixed.

         '../../ui/base/ui_base.gyp:ui_base',
         '../../ui/gfx/gfx.gyp:gfx',
         '../../ui/gfx/gfx.gyp:gfx_geometry',
@@ -268,6 +271,8 @@
         'webui/crw_web_ui_manager.mm',
         'webui/crw_web_ui_page_builder.h',
         'webui/crw_web_ui_page_builder.mm',
+        'webui/mojo_facade.h',
+        'webui/mojo_facade.mm',
         'webui/shared_resources_data_source_ios.h',
         'webui/shared_resources_data_source_ios.mm',
         'webui/url_data_manager_ios.cc',
@@ -363,7 +368,7 @@
       'variables': {
         'closure_entry_point': '__crWeb.webUIBundle',
         'js_bundle_files': [
-          'webui/resources/web_ui_base.js',        
+          'webui/resources/web_ui_base.js',
           'webui/resources/web_ui_bind.js',
           'webui/resources/web_ui_bundle.js',
           'webui/resources/web_ui_favicons.js',
@@ -371,7 +376,7 @@
         ],
       },
       'sources': [
-          'webui/resources/web_ui_base.js',        
+          'webui/resources/web_ui_base.js',
           'webui/resources/web_ui_bind.js',
           'webui/resources/web_ui_bundle.js',
           'webui/resources/web_ui_favicons.js',
@@ -433,6 +438,7 @@
         '../../testing/gtest.gyp:gtest',
         '../../third_party/ocmock/ocmock.gyp:ocmock',
         'ios_web',
+        'test_mojo_bindings',
       ],
       'include_dirs': [
         '../..',
@@ -486,9 +492,22 @@
         'test/web_test_suite.h',
         'test/wk_web_view_crash_utils.h',
         'test/wk_web_view_crash_utils.mm',
+        '<(SHARED_INTERMEDIATE_DIR)/ios/web/test/mojo_test.mojom.cc',
       ],
     },
     {
+      'target_name': 'test_mojo_bindings',
+      # The type of this target must be none. This is so that resources can
+      # depend upon this target for generating the js bindings files. Any
+      # generated cpp files be listed explicitly in browser_ui.

[Ken Rockot(use gerrit already), 2016/05/09 15:44:37]

You should be able to avoid this (manually listing generated source files) by
using mojom_bindings_generator_explicit.gypi. This target type would still be
none (and others could depend on it to trigger JS etc generation), but you would
make a second target as well: a static_library that depends on this one, which
targets can link against if they have link dependencies on the generated cpp
files. There are several examples of this around src/, just grep for
mojom_bindings_generator_explicit.

[Eugene But (OOO till 7-30), 2016/05/10 02:00:55]

If I do this:


    {
      # GN version: //ios/web:test_mojo_bindings_mojom
      'target_name': 'test_mojo_bindings_mojom',
      'type': 'none',
      'variables': {
        'mojom_files': [
          'test/mojo_test.mojom',
        ],
      },
      'include_dirs': [
        '..',
      ],
      'includes': [ '../../mojo/mojom_bindings_generator_explicit.gypi' ],
    },
    {
      # GN version: //ios/web:test_mojo_bindings
      'target_name': 'test_mojo_bindings',
      'type': 'static_library',
      'dependencies': [
        '../../mojo/mojo_base.gyp:mojo_common_lib',
        '../../mojo/mojo_base.gyp:mojo_url_type_converters',
        '../../mojo/mojo_public.gyp:mojo_cpp_bindings',
        'test_mojo_bindings_mojom',
      ],
      'include_dirs': [
        '..',
      ],
    },
Then GYP gives me an error:

gyp: src/ios/web/ios_web_resources.gyp not found

Adding another gyp file and one extra target does not look like a better
approach. Is there any way to avoid adding ios_web_resources just for the test?

[Eugene But (OOO till 7-30), 2016/05/12 20:48:10]

That gyp error was related to other changes. Done.

+      'type': 'none',
+      'sources': [
+        # GN version: TODO
+        'test/mojo_test.mojom',
+      ],
+      'includes': [ '../../mojo/mojom_bindings_generator.gypi' ],
+    },
+    {
       # GN version: //ios/web:user_agent
       'target_name': 'user_agent',
       'type': 'static_library',