Adds a check for classes which require two names to be bound in the c…

…lass body. Ex:

var Foo = class Bar {};
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70662888

src/com/google/javascript/jscomp/Es6ToEs3Converter.java

@@ -548,6 +548,13 @@ private void visitClass(Node classNode, Node parent) {
             + " side of a simple assignment.");
       return;
     }
+
+    if (!className.isEmpty() && !className.getString().equals(fullClassName)) {
+      // cannot bind two class names in the case of: var Foo = class Bar {};
+      cannotConvertYet(classNode, "named class in an assignment");
+      return;
+    }
+
     boolean useUnique = NodeUtil.isStatement(classNode) && !isInFunction(classNode);
     String uniqueFullClassName = useUnique ? getUniqueClassName(fullClassName) : fullClassName;
     String superClassString = superClassName.getQualifiedName();

test/com/google/javascript/jscomp/Es6ToEs3ConverterTest.java

@@ -284,12 +284,8 @@ public void testClassExpressionInAssignment() {
     test("goog.example.C = class { }",
         "/** @constructor @struct */ goog.example.C = function() {}");
 
-    test("goog.example.C = class C { }",
-        "/** @constructor @struct */ goog.example.C = function() {}");
-
-    test("goog.example.C = class C { foo() {} }", Joiner.on('\n').join(
+    test("goog.example.C = class { foo() {} }", Joiner.on('\n').join(
         "/** @constructor @struct */ goog.example.C = function() {}",
-        "",
         "goog.example.C.prototype.foo = function() {};"
     ));
   }
@@ -496,6 +492,12 @@ public void testSuperCall() {
     ));
   }
 
+  public void testMultiNameClass() {
+    test("var F = class G {}", null, Es6ToEs3Converter.CANNOT_CONVERT_YET);
+
+    test("F = class G {}", null, Es6ToEs3Converter.CANNOT_CONVERT_YET);
+  }
+
   public void testClassNested() {
     test("class C { f() { class D {} } }", Joiner.on('\n').join(
         "/** @constructor @struct */",