Implement URL and Origin typemaps/struct traits for blink.

url/url.gyp

Index: url/url.gyp
diff --git a/url/url.gyp b/url/url.gyp
index 1e491f5741d817ccc5498911467054855950ca4e..67871067276296d29a6de42e84734742cbe10da2 100644
--- a/url/url.gyp
+++ b/url/url.gyp
@@ -134,6 +134,22 @@
       'includes': [ '../mojo/mojom_bindings_generator_explicit.gypi' ],
     },
     {
+      'target_name': 'url_interfaces_mojom_for_blink',

[brettw, 2016/05/27 20:15:04]

Can this have a comment about where the GN code is? I don't understand these
mojo things, but you can see the other targets here have comments like:
  # GN version: //url:url_features

[Marijn Kruisselbrink, 2016/05/27 20:29:02]

url_features seems to be the only target that has such a comment, none of the
other targets do.

Also I'm not sure if it really makes sense to try to invent such a mapping for
these mojo targets, as there really isn't any kind of 1:1 mapping. For example
the closest equivalent to this target on the GN side would be the union of
//url/mojo:url_mojom_gurl_blink and //url/mojo::url_mojom_origin_blink, but
those target names don't actually exist anywhere in any of the .gn files
(instead they are generated by the same rules as the non-blink versions). And to
actually use mojo bindings in some other target you'd need to do something very
different in gyp compared to gn anyway.

[Marijn Kruisselbrink, 2016/05/27 20:35:55]

But maybe having a non-perfect match comment is still better than nothing, so
added some GN version comments.

+      'type': 'none',
+      'variables': {
+        'for_blink': 'true',
+        'mojom_files': [
+          'mojo/origin.mojom',
+          'mojo/url.mojom',
+        ],
+        'mojom_typemaps': [
+          '../third_party/WebKit/Source/platform/mojo/KURL.typemap',
+          '../third_party/WebKit/Source/platform/mojo/SecurityOrigin.typemap',
+        ],
+      },
+      'includes': [ '../mojo/mojom_bindings_generator_explicit.gypi' ],
+    },
+    {
       'target_name': 'url_mojom',
       'type': 'static_library',
       'export_dependent_settings': [
@@ -163,6 +179,24 @@
       ],
     },
     {
+      'target_name': 'url_test_interfaces_mojom_for_blink',
+      'type': 'none',
+      'variables': {
+        'for_blink': 'true',
+        'mojom_files': [
+          'mojo/url_test.mojom',
+        ],
+        'mojom_typemaps': [
+          '../third_party/WebKit/Source/platform/mojo/KURL.typemap',
+          '../third_party/WebKit/Source/platform/mojo/SecurityOrigin.typemap',
+        ],
+      },
+      'includes': [ '../mojo/mojom_bindings_generator_explicit.gypi' ],
+      'dependencies': [
+        '../mojo/mojo_public.gyp:mojo_cpp_bindings',
+      ],
+    },
+    {
       'target_name': 'url_test_mojom',
       'type': 'static_library',
       'export_dependent_settings': [