Don't compile media mirroring code on Android.

It's not used. Moving these files and deps to the
enable_extensions branch of the build target matches
what's done in //chrome/browser/media/router/BUILD.gn

Bug: 1057100
Change-Id: I5c3cb21071776a3a22bedbef00ebe998e43e4253
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2364557Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800275}

chrome/browser/BUILD.gn

@@ -646,8 +646,6 @@ static_library("browser") {
     "lookalikes/lookalike_url_tab_storage.h",
     "media/audio_service_util.cc",
     "media/audio_service_util.h",
-    "media/cast_mirroring_service_host.cc",
-    "media/cast_mirroring_service_host.h",
     "media/cast_remoting_connector.cc",
     "media/cast_remoting_connector.h",
     "media/feeds/media_feeds_utils.cc",
@@ -1985,10 +1983,6 @@ static_library("browser") {
     "//components/metrics:net",
     "//components/metrics:ui",
     "//components/metrics_services_manager",
-    "//components/mirroring/browser",
-    "//components/mirroring/mojom:host",
-    "//components/mirroring/mojom:service",
-    "//components/mirroring/service:mirroring_service",
     "//components/navigation_interception",
     "//components/navigation_metrics",
     "//components/net_log",
@@ -4990,6 +4984,10 @@ static_library("browser") {
       "guest_view/web_view/chrome_web_view_permission_helper_delegate.h",
       "guest_view/web_view/context_menu_content_type_web_view.cc",
       "guest_view/web_view/context_menu_content_type_web_view.h",
+
+      # TODO(crbug.com/879012): this shouldn't depend on enable_extensions.
+      "media/cast_mirroring_service_host.cc",
+      "media/cast_mirroring_service_host.h",
       "media/cast_transport_host_filter.cc",
       "media/cast_transport_host_filter.h",
       "media/extension_media_access_handler.cc",
@@ -5172,6 +5170,12 @@ static_library("browser") {
       "//chrome/common/extensions/api:extensions_features",
       "//components/drive",
       "//components/guest_view/browser",
+
+      # TODO(crbug.com/879012): mirroring shouldn't depend on enable_extensions.
+      "//components/mirroring/browser",
+      "//components/mirroring/mojom:host",
+      "//components/mirroring/mojom:service",
+      "//components/mirroring/service:mirroring_service",
       "//extensions/components/javascript_dialog_extensions_client",
       "//google_apis/drive",
       "//media/cast:net",

chrome/browser/media/router/BUILD.gn

@@ -84,6 +84,9 @@ static_library("router") {
       "//components/paint_preview/buildflags",
       "//components/signin/public/base:signin_buildflags",
       "//components/translate/content/common",
+      "//extensions/browser",
+      "//extensions/buildflags",
+      "//extensions/common",
       "//mojo/public/cpp/bindings",
       "//ui/base:buildflags",
     ]

chrome/test/BUILD.gn

@@ -3283,7 +3283,6 @@ test("unit_tests") {
     "../browser/mac/exception_processor_unittest.mm",
     "../browser/mac/keystone_glue_unittest.mm",
     "../browser/media/android/router/media_router_android_unittest.cc",
-    "../browser/media/cast_mirroring_service_host_unittest.cc",
     "../browser/media/history/media_history_keyed_service_unittest.cc",
     "../browser/media/history/media_history_store_unittest.cc",
     "../browser/media/media_engagement_contents_observer_unittest.cc",
@@ -4957,6 +4956,7 @@ test("unit_tests") {
       "../browser/extensions/warning_badge_service_unittest.cc",
       "../browser/extensions/webstore_installer_unittest.cc",
       "../browser/extensions/zipfile_installer_unittest.cc",
+      "../browser/media/cast_mirroring_service_host_unittest.cc",
       "../browser/media/cast_transport_host_filter_unittest.cc",
       "../browser/metrics/extensions_metrics_provider_unittest.cc",
       "../browser/notifications/notification_system_observer_unittest.cc",