Make incremental compilation opt-in.

R=kasperl@google.com

Review URL: https://codereview.chromium.org//344243002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@37604 260f80e4-7a28-3924-810f-c04153c831b5

site/try/src/caching_compiler.dart

@@ -69,11 +69,12 @@ Compiler reuseCompiler(
   Compiler compiler = cachedCompiler;
   if (compiler == null ||
       compiler.libraryRoot != libraryRoot ||
+      !compiler.hasIncrementalSupport ||
       compiler.hasCrashed ||
       compiler.compilerWasCancelled ||
       compiler.enqueuer.resolution.hasEnqueuedEverything ||
       compiler.deferredLoadTask.splitProgram) {
-    if (compiler != null) {
+    if (compiler != null && compiler.hasIncrementalSupport) {
       print('***FLUSH***');
       if (compiler.hasCrashed) {
         print('Unable to reuse compiler due to crash.');

site/try/src/compilation.dart

@@ -33,6 +33,7 @@ import 'ui.dart' show
 
 import 'settings.dart' show
     alwaysRunInWorker,
+    incrementalCompilation,
     minified,
     onlyAnalyze,
     verboseCompiler;
@@ -98,13 +99,14 @@ class CompilationProcess {
     current = this;
     var options = [
         '--analyze-main',
-        '--disable-type-inference',
-        '--incremental-support',
         '--no-source-maps',
     ];
     if (verboseCompiler) options.add('--verbose');
     if (minified) options.add('--minify');
     if (onlyAnalyze) options.add('--analyze-only');
+    if (incrementalCompilation.value) {
+      options.addAll(['--incremental-support', '--disable-type-inference']);
+    }
     interaction.compilationStarting();
     compilerPort.send([['options', options], receivePort.sendPort]);
     receivePort.listen(onMessage);

site/try/src/messages.dart

@@ -32,4 +32,7 @@ const Map<String, dynamic> messages = const <String, dynamic> {
 
   'theme':
     'Theme:',
+
+  'incrementalCompilation':
+    'Enable incremental compilation (EXPERIMENTAL)',
 };

site/try/src/settings.dart

@@ -90,6 +90,9 @@ void set theme(String b) {
 const BooleanUserOption enableCodeCompletion =
     const BooleanUserOption('enableCodeCompletion', isHidden: true);
 
+const BooleanUserOption incrementalCompilation =
+    const BooleanUserOption('incrementalCompilation');
+
 const List<UserOption> options = const <UserOption>[
     _alwaysRunInWorker,
     _verboseCompiler,
@@ -97,6 +100,7 @@ const List<UserOption> options = const <UserOption>[
     _onlyAnalyze,
     _enableDartMind,
     _compilationPaused,
+    incrementalCompilation,
     _codeFont,
     _theme,
     _currentSample,