Split //ios/chrome/browser in multiple targets.

ios/chrome/browser/sessions/BUILD.gn

Index: ios/chrome/browser/sessions/BUILD.gn
diff --git a/ios/chrome/browser/sessions/BUILD.gn b/ios/chrome/browser/sessions/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..f450a53f957fe46463fbe046041791f6d7277ade
--- /dev/null
+++ b/ios/chrome/browser/sessions/BUILD.gn
@@ -0,0 +1,24 @@
+# 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("sessions") {
+  sources = [
+    "ios_chrome_session_tab_helper.h",
+    "ios_chrome_session_tab_helper.mm",
+    "ios_chrome_tab_restore_service_client.h",
+    "ios_chrome_tab_restore_service_client.mm",
+    "ios_chrome_tab_restore_service_factory.cc",
+    "ios_chrome_tab_restore_service_factory.h",
+  ]
+  deps = [
+    "//base",
+    "//components/keyed_service/ios",
+    "//components/sessions",
+    "//ios/chrome/browser:browser_no_public_deps",
+    "//ios/chrome/browser/browser_state",
+    "//ios/public/provider/chrome/browser",
+    "//ios/web",
+    "//url",
+  ]
+}