Upload symbols when uploading mojo binaries to the CDN.

R=viettrungluu@chromium.org

Review URL: https://codereview.chromium.org/1236543003 .
diff --git a/shell/BUILD.gn b/shell/BUILD.gn
index 0c6af58..143ef6d 100644
--- a/shell/BUILD.gn
+++ b/shell/BUILD.gn
@@ -19,6 +19,7 @@
   deps = [
     ":mojo_shell",
     ":tests",
+    ":copy_symbols",
   ]
 
   if (is_android) {
@@ -554,3 +555,30 @@
     "//shell/test:bindings",
   ]
 }
+
+copy("copy_symbols") {
+  testonly = true
+
+  deps = [
+    ":mojo_shell",
+  ]
+  if (is_android) {
+    deps += [ ":bootstrap" ]
+  }
+
+  sources = [
+    "${root_out_dir}/mojo_shell_child",
+  ]
+  if (is_android) {
+    sources += [
+      "${root_out_dir}/libbootstrap.so",
+      "${root_out_dir}/libmojo_shell.so",
+    ]
+  } else {
+    sources += [ "${root_out_dir}/mojo_shell" ]
+  }
+
+  outputs = [
+    "${root_out_dir}/symbols/{{source_file_part}}",
+  ]
+}