Add the "testonly" flag to the GN test target.

Now that the new GN has landed with support for this, we can start using this flag.

R=viettrungluu@chromium.org

Review URL: https://codereview.chromium.org/532423003

Cr-Commit-Position: refs/heads/master@{#293579}

build/config/BUILDCONFIG.gn

@@ -570,8 +570,8 @@ template("component") {
 # TEST SETUP
 # ==============================================================================
 
-# Define a test as an executable. In the future, we'll set "test only" flags
-# on this (when such flags exist) and do something different for Android.
+# Define a test as an executable with the "testonly" flag set. In the future,
+# this will need to be enhanced for Android.
 template("test") {
   executable(target_name) {
     # Configs will always be defined since we set_defaults for a component
@@ -580,6 +580,8 @@ template("test") {
     configs = []  # Prevent list overwriting warning.
     configs = invoker.configs
 
+    testonly = true
+
     # See above call.
     set_sources_assignment_filter([])
 

build/config/android/internal_rules.gni

@@ -79,6 +79,9 @@ template("write_build_config") {
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }
+    if (defined(invoker.testonly)) {
+      testonly = invoker.testonly
+    }
 
     outputs = [
       depfile,

build/config/android/rules.gni

@@ -575,6 +575,7 @@ template("android_java_prebuilt") {
 #   native_libs: List paths of native libraries to include in this apk. If these
 #     libraries depend on other shared_library targets, those dependencies will
 #     also be included in the apk.
+#   testonly: Marks this target as "test-only".
 #
 #   DEPRECATED_java_in_dir: Directory containing java files. All .java files in
 #     this directory will be included in the library. This is only supported to
@@ -647,6 +648,9 @@ template("android_apk") {
     if (defined(invoker.deps)) {
       deps = invoker.deps
     }
+    if (defined(invoker.testonly)) {
+      testonly = invoker.testonly
+    }
 
     native_libs = _native_libs
   }
@@ -801,6 +805,7 @@ template("unittest_apk") {
     if (defined(invoker.deps)) {
       deps = invoker.deps
     }
+    testonly = true
   }
 }
 

mojo/BUILD.gn

@@ -5,6 +5,8 @@
 import("//build/config/ui.gni")
 
 group("mojo") {
+  # Meta-target, don't link into production code.
+  testonly = true
   deps = [
     ":tests",
     "//mojo/common",
@@ -22,6 +24,7 @@ group("mojo") {
 }
 
 group("tests") {
+  testonly = true
   deps = [
     "//mojo/application_manager:mojo_application_manager_unittests",
     "//mojo/apps/js/test:mojo_apps_js_unittests",