Support exporting Mojo bindings for the component build.

third_party/WebKit/public/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.
 
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//third_party/WebKit/Source/config.gni")
 import("//tools/grit/grit_rule.gni")
 
 blink_headers_values = exec_script("//build/gypi_to_gn.py",
                                    [ rebase_path("blink_headers.gypi") ],
@@ skipping 167 matching lines @@
   ]
   public_deps = [
     ":android_mojo_bindings",
     ":new_wrapper_types_mojo_bindings",
     "//cc/ipc:interfaces_surfaceid_only",
     "//device/bluetooth/public/interfaces:bluetooth_mojom_bluetooth_uuid",
     "//url/mojo:url_mojom_origin",
   ]
 
   use_new_wrapper_types = false
+
+  # The chromium variant must be linked with content and use the same export
+  # settings in component build because of the WebBluetoothDeviceId typemap
+  # inside content.
+  export_class_attribute = "CONTENT_EXPORT"
+  export_define = "CONTENT_IMPLEMENTATION=1"
+  export_header = "content/common/content_export.h"
+
+  # Similarly, the blink variant must be linked with the platform component
+  # since it uses types from it in its typemaps.
+  export_class_attribute_blink = "BLINK_PLATFORM_EXPORT"
+  export_define_blink = "BLINK_PLATFORM_IMPLEMENTATION=1"
+  export_header_blink = "third_party/WebKit/public/platform/WebCommon.h"
 }
 
 # GYP version: WebKit/public/blink.gyp:new_wrapper_types_mojo_bindings
 mojom("new_wrapper_types_mojo_bindings") {
   sources = [
     "platform/modules/presentation/presentation.mojom",
   ]
+
+  # See comment above.
+  export_class_attribute = "CONTENT_EXPORT"
+  export_define = "CONTENT_IMPLEMENTATION=1"
+  export_header = "content/common/content_export.h"
+  export_class_attribute_blink = "BLINK_PLATFORM_EXPORT"
+  export_define_blink = "BLINK_PLATFORM_IMPLEMENTATION=1"
+  export_header_blink = "third_party/WebKit/public/platform/WebCommon.h"
 }
 
 # GYP version: WebKit/public/blink.gyp:android_mojo_bindings_java
 mojom("android_mojo_bindings") {
   sources = [
     "platform/modules/payments/payment_request.mojom",
     "platform/modules/webshare/webshare.mojom",
   ]
 
   use_new_wrapper_types = false
+
+  # See comment above.
+  export_class_attribute = "CONTENT_EXPORT"
+  export_define = "CONTENT_IMPLEMENTATION=1"
+  export_header = "content/common/content_export.h"
+  export_class_attribute_blink = "BLINK_PLATFORM_EXPORT"
+  export_define_blink = "BLINK_PLATFORM_IMPLEMENTATION=1"
+  export_header_blink = "third_party/WebKit/public/platform/WebCommon.h"
 }
 
 group("generate_mojo_bindings") {
   deps = [
     ":mojo_bindings_blink__generator",
   ]
 }