Add //components/webdata/common to the GN build.

components/webdata/common/BUILD.gn

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+component("common") {
+  output_name = "webdata_common"
+
+  sources = [
+    "web_database.cc",
+    "web_database.h",
+    "web_database_service.cc",
+    "web_database_service.h",
+    "web_database_table.cc",
+    "web_database_table.h",
+    "web_data_request_manager.cc",
+    "web_data_request_manager.h",
+    "web_data_results.h",
+    "web_data_service_backend.cc",
+    "web_data_service_backend.h",
+    "web_data_service_base.cc",
+    "web_data_service_base.h",
+    "web_data_service_consumer.h",
+    "webdata_constants.cc",
+    "webdata_constants.h",
+    "webdata_export.h",
+  ]
+
+  include_dirs = [
+    "..",

[tfarina, 2014/07/04 23:43:28]

are you sure you need this? I see webdata.gypi has this, but I think GN has this
builtin, so you don't really need this here.

[jbroman, 2014/07/07 14:09:28]

Quite correct. This path isn't even right anymore, since the BUILD.gn file is
not in the same place as the .gyp file. Removed.

+  ]
+
+  defines = [
+    "WEBDATA_IMPLEMENTATION",
+  ]
+
+  deps = [
+    "//base",

[tfarina, 2014/07/04 23:43:28]

the above source list does not need chrome/browser/webdata,
components/autofill/core/browser, components/signin/core/browser?

I checked running the following command line:

$ g grep -h "include \"" components/webdata/common/ | sort | uniq

What gn check says?

+    "//sql",
+  ]
+}