Check in generated Dart bindings and add presubmit script

mojo/dart/packages/mojom/lib/src/generate.dart

 // 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.
 
 /// This library generates Mojo bindings for a Dart package.
 
 library generate;
 
 import 'dart:async';
 import 'dart:convert';
@@ skipping 77 matching lines @@
         oldestModTime = modTime;
       }
       mojomDartCount++;
     }
     return [oldestModTime, mojomDartCount];
   }
 
   // Delete .mojom.dart files under [package] that are [olderThanThis].
   _deleteOldMojomDart(Directory package, DateTime olderThanThis) async {
     Directory libDir = new Directory(path.join(package.path, 'lib'));
-    assert(await libDir.exists());
+    if (!await libDir.exists()) {
+      return;
+    }
     await for (var file in libDir.list(recursive: true, followLinks: false)) {
       if (file is! File) continue;
       if (!isMojomDart(file.path)) continue;
       DateTime modTime = (await file.stat()).modified;
       if (modTime.isBefore(olderThanThis)) {
         log.warning("Deleting stale .mojom.dart: $file");
         await file.delete();
       }
     }
   }
 
   /// If the .mojoms file or the newest .mojom is newer than the oldest
   /// .mojom.dart, then regenerate everything.
   bool _shouldRegenerate(DateTime mojomTime, DateTime mojomDartTime) {
     return (mojomTime == null) ||
         (mojomDartTime == null) ||
         mojomTime.isAfter(mojomDartTime);
   }
 
   _runBindingsGeneration(String script, List<String> arguments) async {
     var result;
     var stopwatch = new Stopwatch()..start();
     result = await Process.run(script, arguments);
     stopwatch.stop();
     _genMs.value += stopwatch.elapsedMilliseconds;
     return result;
   }
 
+  // This is a hack until we can express import paths in .mojom files.
+  // This checks the mojom path for '/mojo/services/' and if found assumes
+  // that is an import path.

[jamesr, 2015/11/17 01:35:07]

i think you accidentally a word or few. maybe "..and if found assumes that
//mojo/services/ is on the import path" ?

[Cutch, 2015/11/17 18:17:15]

Done.

+  String _sniffForMojoServicesInclude(String mojomPath) {
+    List<String> pathComponents = path.split(mojomPath);
+    while (pathComponents.length > 2) {
+      int last = pathComponents.length;
+      if ((pathComponents[last - 1] == 'services') &&
+          (pathComponents[last - 2] == 'mojo')) {
+        return path.joinAll(pathComponents);
+      }
+      // Remove the last element and try again.
+      pathComponents.removeLast();
+    }
+    return null;
+  }
+
   _generateForMojom(File mojom, Directory importDir, Directory destination,
       String packageName) async {
     if (!isMojom(mojom.path)) return;
     log.info("_generateForMojom($mojom)");
 
     final script = path.join(
         _mojoSdk.path, 'tools', 'bindings', 'mojom_bindings_generator.py');
     final sdkInc = path.normalize(path.join(_mojoSdk.path, '..', '..'));
     final outputDir = await destination.createTemp();
     final output = outputDir.path;
+
+    final servicesPath = _sniffForMojoServicesInclude(mojom.path);
+
     final arguments = [
       '--use_bundled_pylibs',
       '-g',
       'dart',
       '-o',
       output,
-      // TODO(zra): Are other include paths needed?
       '-I',
       sdkInc,
       '-I',
-      importDir.path,
-      mojom.path
+      importDir.path
     ];
+    // TODO(zra): Are other include paths needed?

[jamesr, 2015/11/17 01:35:07]

i think we can nuke this for now

[Cutch, 2015/11/17 18:17:15]

Done.

+    if (servicesPath != null) {
+      arguments.add('-I');
+      arguments.add(servicesPath);
+    }
+    arguments.add(mojom.path);
 
     log.info('Generating $mojom');
     log.info('$script ${arguments.join(" ")}');
     log.info('dryRun = $_dryRun');
     if (!_dryRun) {
       final result = await _runBindingsGeneration(script, arguments);
       if (result.exitCode != 0) {
         log.info("bindings generation result = ${result.exitCode}");
         await outputDir.delete(recursive: true);
         throw new GenerationError("$script failed:\n"
@@ skipping 245 matching lines @@
             '\t$dart $packRoot $scriptPath single -m $mojoSdk -r $root '
             '-p $packagePath $skips');
         _errors++;
         return;
       }
     }
   }
 
   bool _shouldSkip(File f) => containsPrefix(f.path, _skip);
 }