Allow building mojo_shell and non-graphical apps/services on a Mac

shell/BUILD.gn

Index: shell/BUILD.gn
diff --git a/shell/BUILD.gn b/shell/BUILD.gn
index 56c6596b7a2dcf4a4bd75664c3d6463b1fad1916..a607a848611dc51fac20b63a4cd7a72910d0b126 100644
--- a/shell/BUILD.gn
+++ b/shell/BUILD.gn
@@ -37,8 +37,11 @@ group("tests") {
     ":mojo_shell_tests",
     ":shell_nfc_apptests",
     "//shell/application_manager:mojo_application_manager_unittests",
-    "//shell/crash:crash_unittests",
   ]
+
+  if (is_android || is_linux) {
+    deps += [ "//shell/crash:crash_unittests" ]
+  }
 }
 
 if (is_android) {
@@ -54,10 +57,13 @@ if (!mojo_use_prebuilt_mojo_shell) {
     "//build/config/sanitizers:deps",
     "//mojo/environment:chromium",
     "//mojo/message_pump",
-    "//shell/crash",
   ]
   shell_common_data_deps = [ ":mojo_shell_child" ]
 
+  if (is_android || is_linux) {
+    shell_common_deps += [ "//shell/crash" ]
+  }
+
   if (is_android) {
     shared_library("mojo_shell") {
       sources = [
@@ -201,6 +207,15 @@ source_set("parent_lib") {
       "//services/native_viewport:lib",
     ]
   }
+
+  if (is_mac) {
+    sources -= [
+      "url_response_disk_cache_loader.cc",
+      "url_response_disk_cache_loader.h",
+    ]
+
+    deps -= [ "//services/url_response_disk_cache" ]
+  }
 }
 
 # This is a separate target mainly since it suppresses check_includes.
@@ -530,6 +545,9 @@ static_library("pingable_app_dummy") {
   public_deps = [
     "//shell/test:pingable_app($default_toolchain)",
   ]
+  sources = [
+    "pingable_app_dummy_empty.cc",
+  ]
 }
 
 embed_file("embed_pingable") {