[Device Discovery] Move files from browser/extensions/api/dial to browser/media/router/discovery/dial

DialMediaSinkService needs to reference DialRegistry and DeviceDescriptionFetcher class. Move them from extension to media router folder so DialMediaSinkService does not depend on files in extension folder. Files moved to media router folder:

chrome/browser/extensions/api/dial/device_description_fetcher.h
chrome/browser/extensions/api/dial/device_description_fetcher.cc
chrome/browser/extensions/api/dial/device_description_fetcher_unittest.cc
chrome/browser/extensions/api/dial/dial_device_data.h
chrome/browser/extensions/api/dial/dial_device_data.cc
chrome/browser/extensions/api/dial/dial_device_data_unittest.cc
chrome/browser/extensions/api/dial/dial_registry.h
chrome/browser/extensions/api/dial/dial_registry.cc
chrome/browser/extensions/api/dial/dial_registry_unittest.cc
chrome/browser/extensions/api/dial/dial_service.h
chrome/browser/extensions/api/dial/dial_service.cc
chrome/browser/extensions/api/dial/dial_service_unittest.cc

Changed namespace to media_router and updated unit tests.

BUG=687375

Review-Url: https://codereview.chromium.org/2756483007
Cr-Commit-Position: refs/heads/master@{#459253}
diff --git a/chrome/browser/extensions/BUILD.gn b/chrome/browser/extensions/BUILD.gn
index 514236c..9193a50 100644
--- a/chrome/browser/extensions/BUILD.gn
+++ b/chrome/browser/extensions/BUILD.gn
@@ -175,18 +175,10 @@
     "api/developer_private/inspectable_views_finder.h",
     "api/developer_private/show_permissions_dialog_helper.cc",
     "api/developer_private/show_permissions_dialog_helper.h",
-    "api/dial/device_description_fetcher.cc",
-    "api/dial/device_description_fetcher.h ",
     "api/dial/dial_api.cc",
     "api/dial/dial_api.h",
     "api/dial/dial_api_factory.cc",
     "api/dial/dial_api_factory.h",
-    "api/dial/dial_device_data.cc",
-    "api/dial/dial_device_data.h",
-    "api/dial/dial_registry.cc",
-    "api/dial/dial_registry.h",
-    "api/dial/dial_service.cc",
-    "api/dial/dial_service.h",
     "api/downloads/downloads_api.cc",
     "api/downloads/downloads_api.h",
     "api/downloads_internal/downloads_internal_api.cc",
@@ -829,6 +821,7 @@
     "//chrome/app/theme:theme_resources",
     "//chrome/app/vector_icons",
     "//chrome/browser/devtools",
+    "//chrome/browser/media/router/discovery",
     "//chrome/common",
     "//chrome/common/extensions/api:api_registration",
     "//chrome/common/extensions/api:extensions_features",