Provide a counter for thrown JavaScript errors per context

src/runtime/runtime-internal.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/conversions.h"
 #include "src/debug/debug.h"
@@ skipping 289 matching lines @@
   HandleScope scope(isolate);
   DCHECK(args.length() == 4);
   CONVERT_INT32_ARG_CHECKED(template_index, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, arg0, 1);
   CONVERT_ARG_HANDLE_CHECKED(String, arg1, 2);
   CONVERT_ARG_HANDLE_CHECKED(String, arg2, 3);
   Handle<String> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result,
       MessageTemplate::FormatMessage(template_index, arg0, arg1, arg2));
+  isolate->native_context()->IncrementErrorsThrown();
   return *result;
 }
 
 
 #define CALLSITE_GET(NAME, RETURN)                          \
   RUNTIME_FUNCTION(Runtime_CallSite##NAME##RT) {            \
     HandleScope scope(isolate);                             \
     DCHECK(args.length() == 1);                             \
     CONVERT_ARG_HANDLE_CHECKED(JSObject, call_site_obj, 0); \
     Handle<String> result;                                  \
@@ skipping 121 matching lines @@
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
   Handle<String> callsite = RenderCallSite(isolate, object);
   THROW_NEW_ERROR_RETURN_FAILURE(
       isolate, NewTypeError(MessageTemplate::kCalledNonCallable, callsite));
 }
 
 }  // namespace internal
 }  // namespace v8