Decompose //extensions/browser/BUILD.gn

extensions/browser/api/web_request/BUILD.gn

+# Copyright 2016 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.
+
+source_set("web_request") {
+  sources = [
+    "form_data_parser.cc",
+    "form_data_parser.h",
+    "upload_data_presenter.cc",
+    "upload_data_presenter.h",
+    "web_request_api.cc",
+    "web_request_api.h",
+    "web_request_api_constants.cc",
+    "web_request_api_constants.h",
+    "web_request_api_helpers.cc",
+    "web_request_api_helpers.h",
+    "web_request_event_details.cc",
+    "web_request_event_details.h",
+    "web_request_event_router_delegate.h",
+    "web_request_permissions.cc",
+    "web_request_permissions.h",
+    "web_request_time_tracker.cc",
+    "web_request_time_tracker.h",
+  ]
+
+  configs += [
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    "//build/config/compiler:no_size_t_to_int_warning",
+  ]
+
+  deps = [
+    "//content/public/browser",
+    "//content/public/common",
+    "//extensions/common/api",
+    "//third_party/re2",
+  ]
+}