Add back --disallow-unsafe-eval for M3. This flag will be temporarily disabled

sdk/lib/_internal/compiler/implementation/dart2js.dart

Index: sdk/lib/_internal/compiler/implementation/dart2js.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/dart2js.dart	(revision 18540)
+++ sdk/lib/_internal/compiler/implementation/dart2js.dart	(working copy)
@@ -151,12 +151,6 @@
     return passThrough('--categories=${categories.join(",")}');
   }
 
-  // TODO(8522): Remove this method once option is restored.
-  complainAboutDisallowUnsafeEval(String argument) {
-    fail('Error: $argument is currently not supported, '
-         'see http://dartbug.com/8522');
-  }
-
   handleShortOptions(String argument) {
     var shortOptions = argument.substring(1).split("");
     for (var shortOption in shortOptions) {
@@ -202,8 +196,7 @@
                       (_) => passThrough('--enable-concrete-type-inference')),
     new OptionHandler(r'--help|/\?|/h', (_) => wantHelp = true),
     new OptionHandler('--package-root=.+|-p.+', setPackageRoot),
-    new OptionHandler('--disallow-unsafe-eval',
-                      complainAboutDisallowUnsafeEval),
+    new OptionHandler('--disallow-unsafe-eval', passThrough),
     new OptionHandler('--analyze-all', passThrough),
     new OptionHandler('--analyze-only', setAnalyzeOnly),
     new OptionHandler('--disable-native-live-type-analysis', passThrough),
@@ -441,18 +434,12 @@
     Disable the optimization that removes unused native types from dart:html
     and related libraries.
 
-'''
-/* TODO(8522): Restore this comment once option is restored.
-'''
   --disallow-unsafe-eval
     Disable dynamic generation of code in the generated output. This is
     necessary to satisfy CSP restrictions (see http://www.w3.org/TR/CSP/).
     This flag is not continuously tested. Please report breakages and we
     will fix them as soon as possible.
 
-'''
-*/
-'''
   --reject-deprecated-language-features
     Reject deprecated language features.  Without this option, the
     compiler will accept language features that are no longer valid