[ios Mojo] Integration test for Mojo WebUI.

ios/web/BUILD.gn

Index: ios/web/BUILD.gn
diff --git a/ios/web/BUILD.gn b/ios/web/BUILD.gn
index e77799d78ff3f3efde6f963328f64581b85f76e4..56f4704d7ed6525b96219740b612865907a26268 100644
--- a/ios/web/BUILD.gn
+++ b/ios/web/BUILD.gn
@@ -472,9 +472,14 @@ test("ios_web_inttests") {
   deps = [
     ":test_support",
     ":web",
+    "test:mojo_bindings",

[sdefresne, 2016/05/28 13:04:01]

Please only use relative name for target defined in the same BUILD.gn file (this
makes it much easier to rename/move targets), so this should be:

    "//ios/web/test:mojo_bindings",
    "//ios/web/test:packed_resources",
    "//ios/web/test:resources",

[Eugene But (OOO till 7-30), 2016/05/31 17:26:57]

Done.

+    "test:packed_resources",
+    "test:resources",
     "//base/test:test_support",
+    "//ios/public/provider/web",
     "//mojo/edk/system",
     "//net:test_support",
+    "//services/shell/public/cpp",
     "//testing/gtest",
     "//ui/base:test_support",
   ]
@@ -482,6 +487,7 @@ test("ios_web_inttests") {
     "browser_state_web_view_partition_inttest.mm",
     "public/test/http_server_inttest.mm",
     "test/run_all_unittests.cc",
+    "webui/web_ui_mojo_inttest.mm",
   ]
 }
 
@@ -537,6 +543,6 @@ grit("resources") {
   ]
   grit_flags = [
     "-E",
-    "root_out_dir=" + rebase_path(root_out_dir, root_build_dir),
+    "root_gen_dir=" + rebase_path(root_out_dir, root_build_dir),

[sdefresne, 2016/05/28 13:04:02]

You want to have the grit variable "root_gen_dir" expands to the value of the gn
variable "root_gen_dir", so you should use the following:

  grit_flags = [
    "-E",
    "root_gen_dir=" + rebase_path(root_gen_dir, root_build_dir),
  ]

If you look at the tool failure, you'll see the error is:
IOError: [Errno 2] No such file or directory:
u'../../out/Release-iphoneos/ios/web/test/mojo_test.mojom.js'

This was because the file tried to include
"${root_gen_dir}/ios/web/test/mojo_test.mojom.js" and "root_gen_dir" grit
variable was expanded from this argument "-E root_gen_dir=../Release-iphoneos"
while it should have been "-E gen".

[Eugene But (OOO till 7-30), 2016/05/31 17:26:57]

Done. Thank you for explanation!

   ]
 }