Add flag to disable string externalization

runtime/vm/dart_api_impl_test.cc

Index: runtime/vm/dart_api_impl_test.cc
diff --git a/runtime/vm/dart_api_impl_test.cc b/runtime/vm/dart_api_impl_test.cc
index 7ccf6a0bda4eafc31c76e30dce7ff954b084e87b..305fc3616724f8c2ead1e535ca4f5e16c0f927ed 100644
--- a/runtime/vm/dart_api_impl_test.cc
+++ b/runtime/vm/dart_api_impl_test.cc
@@ -23,6 +23,7 @@ namespace dart {
 
 DECLARE_FLAG(bool, verify_acquired_data);
 DECLARE_FLAG(bool, ignore_patch_signature_mismatch);
+DECLARE_FLAG(bool, support_externalizable_strings);
 
 #ifndef PRODUCT
 
@@ -5575,6 +5576,8 @@ static Dart_NativeFunction native_args_lookup(Dart_Handle name,
 
 
 TEST_CASE(GetNativeArguments) {
+  FLAG_support_externalizable_strings = true;

[srdjan, 2016/04/07 16:47:36]

It seems that we are not that consistent, but many times we restore the old flag
value before existing the test, so that the local flag value does not escape the
test.

[rmacnak, 2016/04/07 20:22:37]

Added a restore for these changes.

+
   const char* kScriptChars =
       "import 'dart:nativewrappers';"
       "class MyObject extends NativeFieldWrapperClass2 {"
@@ -8497,6 +8500,8 @@ static void MakeExternalCback(void* peer) {
 
 
 TEST_CASE(MakeExternalString) {
+  FLAG_support_externalizable_strings = true;
+
   static int peer8 = 40;
   static int peer16 = 41;
   static int canonical_str_peer = 42;
@@ -8704,6 +8709,8 @@ TEST_CASE(MakeExternalString) {
 
 
 TEST_CASE(ExternalizeConstantStrings) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "String testMain() {\n"
       "  return 'constant string';\n"
@@ -8816,6 +8823,8 @@ static Dart_NativeFunction ExternalStringDeoptimize_native_lookup(
 // Do not use guarding mechanism on externalizable classes, since their class
 // can change on the fly,
 TEST_CASE(GuardExternalizedString) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "main() {\n"
       "  var a = new A('hello');\n"
@@ -8855,6 +8864,8 @@ TEST_CASE(GuardExternalizedString) {
 
 
 TEST_CASE(ExternalStringDeoptimize) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "String str = 'A';\n"
       "class A {\n"
@@ -8890,6 +8901,8 @@ TEST_CASE(ExternalStringDeoptimize) {
 
 
 TEST_CASE(ExternalStringPolymorphicDeoptimize) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "const strA = 'AAAA';\n"
       "class A {\n"
@@ -8926,6 +8939,8 @@ TEST_CASE(ExternalStringPolymorphicDeoptimize) {
 
 
 TEST_CASE(ExternalStringGuardFieldDeoptimize) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "const strA = 'AAAA';\n"
       "class A {\n"
@@ -8967,6 +8982,8 @@ TEST_CASE(ExternalStringGuardFieldDeoptimize) {
 
 
 TEST_CASE(ExternalStringStaticFieldDeoptimize) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "const strA = 'AAAA';\n"
       "class A {\n"
@@ -9003,6 +9020,8 @@ TEST_CASE(ExternalStringStaticFieldDeoptimize) {
 
 
 TEST_CASE(ExternalStringTrimDoubleParse) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "String str = 'A';\n"
       "class A {\n"
@@ -9032,6 +9051,8 @@ TEST_CASE(ExternalStringTrimDoubleParse) {
 
 
 TEST_CASE(ExternalStringDoubleParse) {
+  FLAG_support_externalizable_strings = true;
+
   const char* kScriptChars =
       "String str = 'A';\n"
       "class A {\n"
@@ -9061,7 +9082,7 @@ TEST_CASE(ExternalStringDoubleParse) {
 
 
 TEST_CASE(ExternalStringIndexOf) {
-    const char* kScriptChars =
+  const char* kScriptChars =
       "main(String pattern) {\n"
       "  var str = 'Hello World';\n"
       "  return str.indexOf(pattern);\n"