[Refactor] Update template files for callback functions

third_party/WebKit/Source/bindings/templates/callback_function.cpp.tmpl

 {% from 'utilities.cpp.tmpl' import v8_value_to_local_cpp_value %}
 {% filter format_blink_cpp_source_code %}
 
 {% include 'copyright_block.txt' %}
 
 #include "{{cpp_class}}.h"
 
 {% for filename in cpp_includes %}
 #include "{{filename}}"
 {% endfor %}
 
 namespace blink {
 
 // static
-{{cpp_class}}* {{cpp_class}}::create(ScriptState* scriptState, v8::Local<v8::Value> callback){
+{{cpp_class}}* {{cpp_class}}::create(ScriptState* scriptState, v8::Local<v8::Value> callback) {
   if (isUndefinedOrNull(callback))
     return nullptr;
   return new {{cpp_class}}(scriptState, v8::Local<v8::Function>::Cast(callback));
 }
 
 {{cpp_class}}::{{cpp_class}}(ScriptState* scriptState, v8::Local<v8::Function> callback)
     : m_scriptState(scriptState),
     m_callback(scriptState->isolate(), this, callback) {
   DCHECK(!m_callback.isEmpty());
 }
 
-DEFINE_TRACE({{cpp_class}}) {}
-
 DEFINE_TRACE_WRAPPERS({{cpp_class}}) {
   visitor->traceWrappers(m_callback.cast<v8::Value>());
 }
 
 bool {{cpp_class}}::call({{argument_declarations | join(', ')}}) {
+  if (m_callback.isEmpty())
+    return false;
+
   if (!m_scriptState->contextIsValid())
     return false;
 
   ExecutionContext* context = m_scriptState->getExecutionContext();
   DCHECK(context);
   if (context->isContextSuspended() || context->isContextDestroyed())
     return false;
 
-  if (m_callback.isEmpty())
-    return false;
-
   // TODO(bashi): Make sure that using DummyExceptionStateForTesting is OK.
   // crbug.com/653769
   DummyExceptionStateForTesting exceptionState;
   ScriptState::Scope scope(m_scriptState.get());
+  v8::Isolate* isolate = m_scriptState->isolate();
+
+  v8::Local<v8::Value> thisValue = ToV8(
+      scriptWrappable,
+      m_scriptState->context()->Global(),
+      isolate);
 
   {% for argument in arguments %}
   v8::Local<v8::Value> {{argument.argument_name}} = {{argument.cpp_value_to_v8_value}};
   {% endfor %}
-
-  v8::Local<v8::Value> thisValue = ToV8(scriptWrappable, m_scriptState->context()->Global(), m_scriptState->isolate());
-
   {% if arguments %}
   v8::Local<v8::Value> argv[] = { {{arguments | join(', ', 'argument_name')}} };
   {% else %}
   {# Empty array initializers are illegal, and don\'t compile in MSVC. #}
   v8::Local<v8::Value> *argv = nullptr;
   {% endif %}
+  v8::TryCatch exceptionCatcher(isolate);
+  exceptionCatcher.SetVerbose(true);
 
   v8::Local<v8::Value> v8ReturnValue;
-  v8::TryCatch exceptionCatcher(m_scriptState->isolate());
-  exceptionCatcher.SetVerbose(true);
+  if (!V8ScriptRunner::callFunction(m_callback.newLocal(isolate),
+                                    context,
+                                    thisValue,
+                                    {{arguments | length}},
+                                    argv,
+                                    isolate).ToLocal(&v8ReturnValue)) {
+    return false;
+  }
 
-  if (V8ScriptRunner::callFunction(m_callback.newLocal(m_scriptState->isolate()), m_scriptState->getExecutionContext(), thisValue, {{arguments | length}}, argv, m_scriptState->isolate()).ToLocal(&v8ReturnValue)) {
-    {% if return_value %}
-    {{v8_value_to_local_cpp_value(return_value) | indent(8)}}
-    returnValue = cppValue;
-    {% endif %}
-    return true;
-  }
-  return false;
+  {% if return_value %}
+  {{v8_value_to_local_cpp_value(return_value) | indent(2)}}
+  returnValue = cppValue;
+  {% endif %}
+  return true;
 }
 
 {{cpp_class}}* NativeValueTraits<{{cpp_class}}>::nativeValue(v8::Isolate* isolate, v8::Local<v8::Value> value, ExceptionState& exceptionState) {
   return {{cpp_class}}::create(ScriptState::current(isolate), value);
 }
 
 }  // namespace blink
 
 {% endfilter %}{# format_blink_cpp_source_code #}