Enable tracing in SkyShell

sky/shell/BUILD.gn

Index: sky/shell/BUILD.gn
diff --git a/sky/shell/BUILD.gn b/sky/shell/BUILD.gn
index d6e112f8d2f7526fec474691c1e5e0b99179112f..2cc678f89fae85837c6f5a3ea3cf2a3b85e25a6a 100644
--- a/sky/shell/BUILD.gn
+++ b/sky/shell/BUILD.gn
@@ -10,8 +10,9 @@ import("//build/config/android/rules.gni")
 generate_jni("jni_headers") {
   sources = [
     "org/domokit/sky/shell/JavaServiceProvider.java",
-    "org/domokit/sky/shell/SkyMain.java",
     "org/domokit/sky/shell/PlatformView.java",
+    "org/domokit/sky/shell/SkyMain.java",
+    "org/domokit/sky/shell/TracingController.java",
   ]
   jni_package = "sky/shell"
 }
@@ -35,6 +36,8 @@ shared_library("sky_shell") {
     "shell.h",
     "sky_main.cc",
     "sky_main.h",
+    "tracing_controller.cc",
+    "tracing_controller.h",
     "ui/animator.cc",
     "ui/animator.h",
     "ui/engine.cc",
@@ -80,6 +83,7 @@ android_library("java") {
     "org/domokit/sky/shell/SkyActivity.java",
     "org/domokit/sky/shell/SkyApplication.java",
     "org/domokit/sky/shell/SkyMain.java",
+    "org/domokit/sky/shell/TracingController.java",
   ]
 
   deps = [