Reland: Add a use counter for Intl.v8BreakIterator

This relands https://codereview.chromium.org/619913002/
The test has been fixed to do a GC so it does not appear to leak in
ASAN.  In addition the test has been fixed to work in the no-i18n
build, by incorporating the change from https://codereview.chromium.org/631743002/
R=ishell@chromium.org
BUG=

Review URL: https://codereview.chromium.org/628223002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24423 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -4528,6 +4528,7 @@ class V8_EXPORT Isolate {
    */
   enum UseCounterFeature {
     kUseAsm = 0,
+    kBreakIterator = 1,
     kUseCounterFeatureCount  // This enum value must be last.
   };
 

src/i18n.cc

@@ -631,6 +631,8 @@ icu::BreakIterator* CreateICUBreakIterator(
     return NULL;
   }
 
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kBreakIterator);
+
   return break_iterator;
 }
 

test/cctest/test-strings.cc

@@ -1292,6 +1292,42 @@ TEST(RobustSubStringStub) {
 }
 
 
+namespace {
+
+int* global_use_counts = NULL;
+
+void MockUseCounterCallback(v8::Isolate* isolate,
+                            v8::Isolate::UseCounterFeature feature) {
+  ++global_use_counts[feature];
+}
+}
+
+
+TEST(CountBreakIterator) {
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  LocalContext context;
+  int use_counts[v8::Isolate::kUseCounterFeatureCount] = {};
+  global_use_counts = use_counts;
+  CcTest::isolate()->SetUseCounterCallback(MockUseCounterCallback);
+  CHECK_EQ(0, use_counts[v8::Isolate::kBreakIterator]);
+  v8::Local<v8::Value> result = CompileRun(
+      "(function() {"
+      "  if (!this.Intl) return 0;"
+      "  var iterator = Intl.v8BreakIterator(['en']);"
+      "  iterator.adoptText('Now is the time');"
+      "  iterator.next();"
+      "  return iterator.next();"
+      "})();");
+  CHECK(result->IsNumber());
+  int uses = result->ToInt32()->Value() == 0 ? 0 : 1;
+  CHECK_EQ(uses, use_counts[v8::Isolate::kBreakIterator]);
+  // Make sure GC cleans up the break iterator, so we don't get a memory leak
+  // reported by ASAN.
+  CcTest::isolate()->LowMemoryNotification();
+}
+
+
 TEST(StringReplaceAtomTwoByteResult) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());