Version 2.12.0-270.0.dev

Merge commit 'e0cd4b37cfc8a1fbc205fa1fd89c082c439db4ad' into 'dev'
diff --git a/pkg/_js_interop_checks/lib/js_interop_checks.dart b/pkg/_js_interop_checks/lib/js_interop_checks.dart
index e3f0978..b936c44 100644
--- a/pkg/_js_interop_checks/lib/js_interop_checks.dart
+++ b/pkg/_js_interop_checks/lib/js_interop_checks.dart
@@ -30,6 +30,9 @@
   bool _classHasAnonymousAnnotation = false;
   bool _libraryHasJSAnnotation = false;
   bool _libraryIsGlobalNamespace = false;
+  // TODO(srujzs): This currently disables this check always. This check should
+  // instead only be disabled up until a given language version.
+  bool _disableJSNativeClassConflict = true;
 
   JsInteropChecks(
       this._coreTypes, this._diagnosticsReporter, this._nativeClasses);
@@ -83,7 +86,8 @@
             cls.location.file);
       }
     }
-    if (_classHasJSAnnotation &&
+    if (!_disableJSNativeClassConflict &&
+        _classHasJSAnnotation &&
         !_classHasAnonymousAnnotation &&
         _libraryIsGlobalNamespace) {
       var jsClass = getJSName(cls);
diff --git a/tools/VERSION b/tools/VERSION
index 6d46558..bc70d09 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 12
 PATCH 0
-PRERELEASE 269
+PRERELEASE 270
 PRERELEASE_PATCH 0
\ No newline at end of file