Use dictionaries for context creation attributes. Eliminate custom bindings.

Source/bindings/templates/dictionary_v8.cpp

Index: Source/bindings/templates/dictionary_v8.cpp
diff --git a/Source/bindings/templates/dictionary_v8.cpp b/Source/bindings/templates/dictionary_v8.cpp
index c2e6ef1b96f7e498460f080a608721fb1d1aa5be..6502ef65556ebdf92b93f6bf2768884e6a8a240e 100644
--- a/Source/bindings/templates/dictionary_v8.cpp
+++ b/Source/bindings/templates/dictionary_v8.cpp
@@ -20,7 +20,11 @@ void {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Handle<v8::Value> v8Value, {
     if (isUndefinedOrNull(v8Value))
         return;
     if (!v8Value->IsObject()) {
+        {% if use_permissive_dictionary_conversion %}
+        // Do nothing.
+        {% else %}
         exceptionState.throwTypeError("cannot convert to dictionary.");
+        {% endif %}
         return;
     }