[ios] Adds code to support the iOS Handoff feature.

ios/chrome/browser/device_sharing/BUILD.gn

Index: ios/chrome/browser/device_sharing/BUILD.gn
diff --git a/ios/chrome/browser/itunes_links/BUILD.gn b/ios/chrome/browser/device_sharing/BUILD.gn
similarity index 51%
copy from ios/chrome/browser/itunes_links/BUILD.gn
copy to ios/chrome/browser/device_sharing/BUILD.gn
index a4abdb0862a4cc7ed02f0fa518ac4204576923c3..6c10dd99ba3386f297b49b2003ea652bb2a22b38 100644
--- a/ios/chrome/browser/itunes_links/BUILD.gn
+++ b/ios/chrome/browser/device_sharing/BUILD.gn
@@ -2,15 +2,19 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("itunes_links") {
+source_set("device_sharing") {
   sources = [
-    "itunes_links_observer.h",
-    "itunes_links_observer.mm",
+    "device_sharing_manager.h",
+    "device_sharing_manager.mm",
   ]
   deps = [
     "//base",
+    "//components/handoff",
+    "//components/prefs",
     "//ios/chrome/browser",
-    "//ios/web",
+    "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/prefs",
+    "//net",
     "//url",
   ]
 }
@@ -18,12 +22,15 @@ source_set("itunes_links") {
 source_set("unit_tests") {
   testonly = true
   sources = [
-    "itunes_links_observer_unittest.mm",
+    "device_sharing_manager_unittest.mm",
   ]
   deps = [
-    ":itunes_links",
+    ":device_sharing",
     "//base",
+    "//components/handoff",
+    "//components/sync_preferences:test_support",
     "//ios/chrome/browser",
+    "//ios/chrome/browser/browser_state:test_support",
     "//ios/web:test_support",
     "//testing/gtest",
     "//third_party/ocmock",