Fix flakyness in tests: make sure to garbage collect temporary test

external strings so that they are not disposed when running other
tests that rely on only one external string being disposed during its
run.

TBR=kasperl
Review URL: http://codereview.chromium.org/118158

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2095 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/cctest/test-api.cc

@@ -538,29 +538,36 @@ THREADED_TEST(ScriptMakingExternalAsciiString) {
 
 
 THREADED_TEST(UsingExternalString) {
-  v8::HandleScope scope;
-  uint16_t* two_byte_string = AsciiToTwoByteString("test string");
-  Local<String> string = String::NewExternal(new TestResource(two_byte_string));
-  i::Handle<i::String> istring = v8::Utils::OpenHandle(*string);
-  // Trigger GCs so that the newly allocated string moves to old gen.
-  i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in survivor space now
-  i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in old gen now
-  i::Handle<i::String> isymbol = i::Factory::SymbolFromString(istring);
-  CHECK(isymbol->IsSymbol());
+  {
+    v8::HandleScope scope;
+    uint16_t* two_byte_string = AsciiToTwoByteString("test string");
+    Local<String> string =
+        String::NewExternal(new TestResource(two_byte_string));
+    i::Handle<i::String> istring = v8::Utils::OpenHandle(*string);
+    // Trigger GCs so that the newly allocated string moves to old gen.
+    i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in survivor space now
+    i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in old gen now
+    i::Handle<i::String> isymbol = i::Factory::SymbolFromString(istring);
+    CHECK(isymbol->IsSymbol());
+  }
+  i::Heap::CollectAllGarbage();
 }
 
 
 THREADED_TEST(UsingExternalAsciiString) {
-  v8::HandleScope scope;
-  const char* one_byte_string = "test string";
-  Local<String> string = String::NewExternal(
-      new TestAsciiResource(i::StrDup(one_byte_string)));
-  i::Handle<i::String> istring = v8::Utils::OpenHandle(*string);
-  // Trigger GCs so that the newly allocated string moves to old gen.
-  i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in survivor space now
-  i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in old gen now
-  i::Handle<i::String> isymbol = i::Factory::SymbolFromString(istring);
-  CHECK(isymbol->IsSymbol());
+  {
+    v8::HandleScope scope;
+    const char* one_byte_string = "test string";
+    Local<String> string = String::NewExternal(
+        new TestAsciiResource(i::StrDup(one_byte_string)));
+    i::Handle<i::String> istring = v8::Utils::OpenHandle(*string);
+    // Trigger GCs so that the newly allocated string moves to old gen.
+    i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in survivor space now
+    i::Heap::CollectGarbage(0, i::NEW_SPACE);  // in old gen now
+    i::Handle<i::String> isymbol = i::Factory::SymbolFromString(istring);
+    CHECK(isymbol->IsSymbol());
+  }
+  i::Heap::CollectAllGarbage();
 }