[Extenisons Bindings] Don't throw unchecked errors; add console errors

extensions/renderer/native_extension_bindings_system.cc

Index: extensions/renderer/native_extension_bindings_system.cc
diff --git a/extensions/renderer/native_extension_bindings_system.cc b/extensions/renderer/native_extension_bindings_system.cc
index 9924a14e59e5d381e66c604b9b5ec04c55417973..87ee7f8ce8fe7423ef39a788a62aed026e38948c 100644
--- a/extensions/renderer/native_extension_bindings_system.cc
+++ b/extensions/renderer/native_extension_bindings_system.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
+#include "content/public/common/console_message_level.h"
 #include "content/public/common/content_switches.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/event_filtering_info.h"
@@ -164,6 +165,14 @@ v8::Global<v8::Value> CallJsFunctionSync(v8::Local<v8::Function> function,
   return result;
 }
 
+void AddConsoleError(v8::Local<v8::Context> context, const std::string& error) {
+  ScriptContext* script_context =
+      ScriptContextSet::GetContextByV8Context(context);
+  CHECK(script_context);
+  script_context->AddMessageToConsole(content::CONSOLE_MESSAGE_LEVEL_ERROR,
+                                      error);
+}
+
 // Returns the API schema indicated by |api_name|.
 const base::DictionaryValue& GetAPISchema(const std::string& api_name) {
   const base::DictionaryValue* schema =
@@ -335,7 +344,7 @@ NativeExtensionBindingsSystem::NativeExtensionBindingsSystem(
                      base::Unretained(this)),
           base::Bind(&NativeExtensionBindingsSystem::OnEventListenerChanged,
                      base::Unretained(this)),
-          APILastError(base::Bind(&GetRuntime))),
+          APILastError(base::Bind(&GetRuntime), base::Bind(&AddConsoleError))),
       weak_factory_(this) {
   api_system_.RegisterCustomType("storage.StorageArea",
                                  base::Bind(&StorageArea::CreateStorageArea));