Automated g4 rollback of changelist 184019882.

*** Reason for rollback ***

Creates a release blocker that needs fixing before rolling forward.

*** Original change description ***

Fix bug in the old type checker where a stub method definition causes loss of type checking.

***

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=184218181

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

@@ -1806,22 +1806,6 @@ private ObjectType getObjectSlot(String slotName) {
       return null;
     }
 
-    /**
-     * When a class has a stub for a property, and the property exists on a super interface,
-     * use that type.
-     */
-    private JSType getInheritedInterfacePropertyType(ObjectType obj, String propName) {
-      if (obj != null && obj.isPrototypeObject()) {
-        FunctionType f = obj.getOwnerFunction();
-        for (ObjectType i : f.getImplementedInterfaces()) {
-          if (i.hasProperty(propName)) {
-            return i.getPropertyType(propName);
-          }
-        }
-      }
-      return null;
-    }
-
     /**
      * Resolve any stub declarations to unknown types if we could not
      * find types for them during traversal.
@@ -1842,19 +1826,17 @@ void resolveStubDeclarations() {
         // If we see a stub property, make sure to register this property
         // in the type registry.
         ObjectType ownerType = getObjectSlot(ownerName);
-        JSType inheritedType = getInheritedInterfacePropertyType(ownerType, propName);
-        JSType stubType = inheritedType == null ? unknownType : inheritedType;
-        defineSlot(n, parent, stubType, true);
+        defineSlot(n, parent, unknownType, true);
 
         if (ownerType != null &&
             (isExtern || ownerType.isFunctionPrototypeType())) {
           // If this is a stub for a prototype, just declare it
           // as an unknown type. These are seen often in externs.
           ownerType.defineInferredProperty(
-              propName, stubType, n);
+              propName, unknownType, n);
         } else {
           typeRegistry.registerPropertyOnType(
-              propName, ownerType == null ? stubType : ownerType);
+              propName, ownerType == null ? unknownType : ownerType);
         }
       }
     }

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

@@ -2951,47 +2951,6 @@ public void testStubFunctionDeclaration10() {
         "function(number): number");
   }
 
-
-  public void testStubMethodDeclarationDoesntBlockTypechecking_1() {
-    testTypes(
-        lines(
-            "/** @interface */",
-            "function Foo() {}",
-            "/** @return {number} */",
-            "Foo.prototype.method = function() {};",
-            "/**",
-            " * @constructor",
-            " * @implements {Foo}",
-            " */",
-            "function Bar() {}",
-            "Bar.prototype.method;",
-            "var /** null */ n = (new Bar).method();"),
-        lines(
-            "initializing variable",
-            "found   : number",
-            "required: null"));
-  }
-
-  public void testStubMethodDeclarationDoesntBlockTypechecking_2() {
-    testTypes(
-        lines(
-            "/** @constructor */",
-            "function Foo() {}",
-            "/** @return {number} */",
-            "Foo.prototype.method = function() {};",
-            "/**",
-            " * @constructor",
-            " * @extends {Foo}",
-            " */",
-            "function Bar() {}",
-            "Bar.prototype.method;",
-            "var /** null */ n = (new Bar).method();"),
-        lines(
-            "initializing variable",
-            "found   : number",
-            "required: null"));
-  }
-
   public void testNestedFunctionInference1() {
     String nestedAssignOfFooAndBar =
         "/** @constructor */ function f() {};" +