Automated g4 rollback of changelist 195872147.

*** Reason for rollback ***

Breaks some typescript builds

*** Original change description ***

Declare externs on the global `this` when window is not present.

This fix an issue where externs weren't assumed to be propeties on any object
when `window` is absent from the externs. This could cause the compiler to
improperly rename properties which are actually references to externs.

***

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=195893567

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

@@ -31,8 +31,6 @@
  */
 class DeclaredGlobalExternsOnWindow implements CompilerPass, NodeTraversal.Callback {
 
-  private static final String WINDOW_NAME = "window";
-
   private final AbstractCompiler compiler;
   private final Set<Node> nodes = new LinkedHashSet<>();
 
@@ -50,21 +48,23 @@ public void process(Node externs, Node root) {
   }
 
   private void addWindowProperties() {
-    if (!nodes.isEmpty()) {
+    if (!nodes.isEmpty() && windowInExterns) {
       for (Node node : nodes) {
-        addExtern(node, windowInExterns);
+        addExtern(node);
         compiler.reportChangeToEnclosingScope(node);
       }
     }
   }
 
-  private static void addExtern(Node node, boolean defineOnWindow) {
+  private static void addExtern(Node node) {
     String name = node.getString();
     JSDocInfo oldJSDocInfo = NodeUtil.getBestJSDocInfo(node);
 
-    Node globalRef = defineOnWindow ? IR.name(WINDOW_NAME) : IR.thisNode();
+    // TODO(tbreisacher): Consider adding externs to 'this' instead of 'window',
+    // for environments where the global object is not called 'window.'
+    Node window = IR.name("window");
     Node string = IR.string(name);
-    Node getprop = IR.getprop(globalRef, string);
+    Node getprop = IR.getprop(window, string);
     Node newNode = getprop;
 
     if (oldJSDocInfo != null) {
@@ -131,7 +131,7 @@ public void visit(NodeTraversal t, Node n, Node parent) {
       nodes.add(n.getFirstChild());
     } else if (n.isVar()) {
       for (Node c : n.children()) {
-        if (c.getString().equals(WINDOW_NAME)) {
+        if (c.getString().equals("window")) {
           windowInExterns = true;
           continue;
         }

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

@@ -43,9 +43,9 @@ public void testWindowProperty1a() {
     testExternChanges("var window; var a;", "", "var window;var a;window.a");
   }
 
-  // No "var window;" so use "this" instead.
+  // No "var window;" so this is a no-op.
   public void testWindowProperty1b() {
-    testExternChanges("var a;", "", "var a;this.a");
+    testExternChanges("var a", "", "var a");
   }
 
   public void testWindowProperty2() {
@@ -57,9 +57,9 @@ public void testWindowProperty3a() {
         "var window;function f(){}window.f;");
   }
 
-  // No "var window;" so use "this" instead.
+  // No "var window;" so this is a no-op.
   public void testWindowProperty3b() {
-    testExternChanges("function f() {}", "var b", "function f(){}this.f");
+    testExternChanges("function f() {}", "var b", "function f(){}");
   }
 
   public void testWindowProperty4() {
@@ -73,9 +73,9 @@ public void testWindowProperty5a() {
         "var window;var x=function(){};window.x;");
   }
 
-  // No "var window;" so use "this" instead.
+  // No "var window;" so this is a no-op.
   public void testWindowProperty5b() {
-    testExternChanges("var x = function f() {};", "var b", "var x=function f(){};this.x");
+    testExternChanges("var x = function f() {}", "var b", "var x=function f(){}");
   }
 
   public void testWindowProperty5c() {

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

@@ -2013,11 +2013,11 @@ public void testClassWithGettersIsRemoved() {
     // Investigate why are they kept when ran together with other passes.
     String expected =
         LINE_JOINER.join(
-            "('undefined'!=typeof window&&window===this?this:'undefined'!=typeof ",
-            "global&&null!=global?global:this).",
-            "Object.defineProperties(function() {},",
-            "{d:{a:!0,b:!0,c:function(){}},", // renamed from init
-            "e:{a:!0,b:!0,f:function(){}}})"); // renamed from prop
+        "('undefined'!=typeof window&&window===this?this:'undefined'!=typeof ",
+        "global&&null!=global?global:this).",
+        "c.defineProperties(function() {},",
+        "{e:{a:!0,b:!0,d:function(){}},",  // renamed from init
+        "f:{a:!0,b:!0,g:function(){}}})");  // renamed from prop
 
     options.setLanguageIn(LanguageMode.ECMASCRIPT_2015);
     options.setLanguageOut(LanguageMode.ECMASCRIPT5);
@@ -5141,6 +5141,7 @@ protected CompilerOptions createCompilerOptions() {
     options.setDevMode(DevMode.EVERY_PASS);
     options.setCodingConvention(new GoogleCodingConvention());
     options.setRenamePrefixNamespaceAssumeCrossModuleNames(true);
+    options.declaredGlobalExternsOnWindow = false;
     return options;
   }
 }

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

@@ -89,9 +89,8 @@ public void testGlobalVar() throws Exception {
   }
 
   public void testGlobalThisReferences() throws Exception {
-    SymbolTable table = createSymbolTable(
-        "var x = this; function f() { return this + this + this; }",
-        /* externsCode= */ "");
+    SymbolTable table =
+        createSymbolTable("var x = this; function f() { return this + this + this; }");
 
     Symbol global = getGlobalVar(table, "*global*");
     assertNotNull(global);
@@ -102,7 +101,7 @@ public void testGlobalThisReferences() throws Exception {
 
   public void testGlobalThisReferences2() throws Exception {
     // Make sure the global this is declared, even if it isn't referenced.
-    SymbolTable table = createSymbolTable("", /* externsCode= */ "");
+    SymbolTable table = createSymbolTable("");
 
     Symbol global = getGlobalVar(table, "*global*");
     assertNotNull(global);
@@ -112,8 +111,7 @@ public void testGlobalThisReferences2() throws Exception {
   }
 
   public void testGlobalThisReferences3() throws Exception {
-    SymbolTable table =
-        createSymbolTable("this.foo = {}; this.foo.bar = {};", /* externsCode= */ "");
+    SymbolTable table = createSymbolTable("this.foo = {}; this.foo.bar = {};");
 
     Symbol global = getGlobalVar(table, "*global*");
     assertNotNull(global);
@@ -345,7 +343,7 @@ public void testGlobalVarInExterns() throws Exception {
     SymbolTable table = createSymbolTable("customExternFn(1);");
     Symbol fn = getGlobalVar(table, "customExternFn");
     List<Reference> refs = table.getReferenceList(fn);
-    assertThat(refs).hasSize(3);
+    assertThat(refs).hasSize(2);
 
     SymbolScope scope = table.getEnclosingScope(refs.get(0).getNode());
     assertTrue(scope.isGlobalScope());
@@ -1186,15 +1184,6 @@ private SymbolTable createSymbolTable(String input) {
     return assertSymbolTableValid(compiler.buildKnownSymbolTable());
   }
 
-  private SymbolTable createSymbolTable(String input, String externsCode) {
-    List<SourceFile> inputs = ImmutableList.of(SourceFile.fromCode("in1", input));
-    List<SourceFile> externs = ImmutableList.of(SourceFile.fromCode("externs1", externsCode));
-
-    Compiler compiler = new Compiler(new BlackHoleErrorManager());
-    compiler.compile(externs, inputs, options);
-    return assertSymbolTableValid(compiler.buildKnownSymbolTable());
-  }
-
   /**
    * Asserts that the symbol table meets some invariants. Returns the same table for easy chaining.
    */