Fix inefficient validation of template strings (don't call getChildCo…

…unt and getChildAtIndex for each child).

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=130889034

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

@@ -405,16 +405,16 @@ private void validateImport(Node n) {
 
   private void validateImportSpecifiers(Node n) {
     validateNodeType(Token.IMPORT_SPECS, n);
-    for (Node child : n.children()) {
-      validateImportSpecifier(child);
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
+      validateImportSpecifier(c);
     }
   }
 
   private void validateImportSpecifier(Node n) {
     validateNodeType(Token.IMPORT_SPEC, n);
     validateChildCountIn(n, 1, 2);
-    for (Node child : n.children()) {
-      validateName(child);
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
+      validateName(c);
     }
   }
 
@@ -442,16 +442,16 @@ private void validateExport(Node n, boolean isAmbient) {
 
   private void validateExportSpecifiers(Node n) {
     validateNodeType(Token.EXPORT_SPECS, n);
-    for (Node child : n.children()) {
-      validateExportSpecifier(child);
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
+      validateExportSpecifier(c);
     }
   }
 
   private void validateExportSpecifier(Node n) {
     validateNodeType(Token.EXPORT_SPEC, n);
     validateChildCountIn(n, 1, 2);
-    for (Node child : n.children()) {
-      validateName(child);
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
+      validateName(c);
     }
   }
 
@@ -469,8 +469,8 @@ private void validateTemplateLit(Node n) {
     if (!n.hasChildren()) {
       return;
     }
-    for (int i = 0; i < n.getChildCount(); i++) {
-      Node child = n.getChildAtIndex(i);
+    int i = 0;
+    for (Node child = n.getFirstChild(); child != null; child = child.getNext(), i++) {
       // If the first child is not a STRING, this is a tagged template.
       if (i == 0 && !child.isString()) {
         validateExpression(child);
@@ -505,15 +505,15 @@ private void validateInterface(Node n) {
 
   private void validateInterfaceExtends(Node n) {
     validateNodeType(Token.INTERFACE_EXTENDS, n);
-    for (Node child : n.children()) {
-      validateNamedType(child);
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
+      validateNamedType(c);
     }
   }
 
   private void validateInterfaceMembers(Node n) {
     validateNodeType(Token.INTERFACE_MEMBERS, n);
-    for (Node child : n.children()) {
-      validateInterfaceMember(child);
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
+      validateInterfaceMember(c);
     }
   }
 
@@ -546,8 +546,8 @@ private void validateEnum(Node n) {
 
   private void validateEnumMembers(Node n) {
     validateNodeType(Token.ENUM_MEMBERS, n);
-    for (Node child : n.children()) {
-      validateObjectLitStringKey(child);
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
+      validateObjectLitStringKey(c);
     }
   }
 
@@ -588,7 +588,7 @@ private void validateClassHelper(Node n, boolean isAmbient) {
 
   private void validateClassMembers(Node n, boolean isAmbient) {
     validateNodeType(Token.CLASS_MEMBERS, n);
-    for (Node c : n.children()) {
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
       validateClassMember(c, isAmbient);
     }
   }
@@ -1419,11 +1419,11 @@ private void validateNamespaceName(Node n) {
 
   private void validateNamespaceElements(Node n, boolean isAmbient) {
     validateNodeType(Token.NAMESPACE_ELEMENTS, n);
-    for (Node child : n.children()) {
+    for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
       if (isAmbient) {
-        validateAmbientDeclarationHelper(child);
+        validateAmbientDeclarationHelper(c);
       } else {
-        validateStatement(child);
+        validateStatement(c);
       }
     }
   }
@@ -1471,9 +1471,7 @@ private void validateMinimumChildCount(Node n, int i) {
     }
 
     if (!valid) {
-      violation(
-          "Expected at least " + i + " children, but was "
-              + n.getChildCount(), n);
+      violation("Expected at least " + i + " children, but was " + n.getChildCount(), n);
     }
   }
 
@@ -1487,9 +1485,7 @@ private void validateMaximumChildCount(Node n, int i) {
       valid = n.getChildCount() <= i;
     }
     if (!valid) {
-      violation(
-          "Expected no more than " + i + " children, but was "
-              + n.getChildCount(), n);
+      violation("Expected no more than " + i + " children, but was " + n.getChildCount(), n);
     }
   }