Don't run commands that require java unless run_jscompile is true.

remoting/webapp/build_template.gni

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Keep in sync with 'remoting_webapp' target in remoting/remoting_client.gypi.
 
 import("//build/config/chrome_build.gni")
 import("//remoting/remoting_locales.gni")
 import("//remoting/remoting_options.gni")
 import("//remoting/remoting_version.gni")
@@ skipping 29 matching lines @@
       rebase_path(webapp_locale_dir, root_build_dir) +
           "/@{json_suffix}/messages.json",
       "--locales_listfile",
       rebase_path(locales_listfile_output, root_build_dir),
     ]
     args += remoting_locales
   }
 }
 
 template("build_webapp_html") {
-  target_jscompile = "${target_name}_jscompile"
-  target_jscompile_stamp = "$target_gen_dir/${target_jscompile}.stamp"
-  action(target_jscompile) {
-    js_files = remoting_webapp_js_proto_files + invoker.js_files
+  target_jscompile = ""
 
-    script = "../../third_party/closure_compiler/compile.py"
-    inputs = js_files
-    outputs = [
-      target_jscompile_stamp,
-    ]
+  if (run_jscompile) {
+    target_jscompile = "${target_name}_jscompile"
+    target_jscompile_stamp = "$target_gen_dir/${target_jscompile}.stamp"
+    action(target_jscompile) {
+      js_files = remoting_webapp_js_proto_files + invoker.js_files
 
-    args = [
-             "--strict",
-             "--no-single-file",
-             "--externs",
-             "../../third_party/closure_compiler/externs/chrome_extensions.js",
-             "--success-stamp",
-             rebase_path(target_jscompile_stamp, root_build_dir),
-           ] + rebase_path(js_files, root_build_dir)
+      script = "../../third_party/closure_compiler/compile.py"
+      inputs = js_files
+      outputs = [
+        target_jscompile_stamp,
+      ]
+
+      args = [
+        "--strict",
+        "--no-single-file",
+        "--externs",
+        "../../third_party/closure_compiler/externs/chrome_extensions.js",
+        "--success-stamp",
+        rebase_path(target_jscompile_stamp, root_build_dir),
+      ]
+      args += rebase_path(js_files, root_build_dir)
+    }
   }
 
   action(target_name) {
     html_template_file = invoker.html_template_file
     html_template_include_files = invoker.html_template_include_files
     js_files = invoker.js_files
     html_output = invoker.html_output
 
     script = "build-html.py"
 
     inputs = [ html_template_file ] + html_template_include_files + js_files
 
     outputs = [
       html_output,
     ]
 
-    if (run_jscompile) {
+    if (target_jscompile != "") {

[garykac, 2015/06/05 21:09:35]

I actually don't like this because it now takes more effort for someone reading
this code to find all the parts affected by the run_jscompile flag. It's now
implicit instead of explicit. Just so we can work around bogus warnings from GN.

but lgtm'ing to unblock Nico

[Dan Beam, 2015/06/05 21:14:51]

I think it reads OK: if there's something to compile, do it.

There's really not a ton of uses of this variable.

       deps = [
         ":$target_jscompile",
       ]
     }
 
     args = [
       rebase_path(html_output, root_build_dir),
       rebase_path(html_template_file, root_build_dir),
     ]
     args += [
@@ skipping 307 matching lines @@
     args += [
       "--manifest_key",
       manifest_key,
     ]
     args += [
       "--app_client_id",
       app_client_id,
     ]
   }
 }