bindings: Support sequence in callback function arguments

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

 {% from 'utilities.cpp' import v8_value_to_local_cpp_value %}
 {% filter format_blink_cpp_source_code %}
 
 {% include 'copyright_block.txt' %}
 
 #include "{{v8_class}}.h"
 
 {% for filename in cpp_includes %}
 #include "{{filename}}"
 {% endfor %}
@@ skipping 11 matching lines @@
 {
 }
 
 bool {{v8_class}}::call({{argument_declarations | join(', ')}})
 {
     if (!scriptState->contextIsValid())
         return false;
 
     if (m_callback.isEmpty())
         return false;
+
     ScriptState::Scope scope(scriptState);
 
     {% for argument in arguments %}
     v8::Local<v8::Value> {{argument.argument_name}} = {{argument.cpp_value_to_v8_value}};
     {% endfor %}
     {% 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::Local<v8::Value> v8ReturnValue;
     v8::TryCatch exceptionCatcher(scriptState->isolate());
-    exceptionCatcher.SetVerbose(true);

[bashi, 2016/09/23 01:47:10]

Removed SetVerbose(true) call because the testharness (layout test) fails with a
mysterious error message (It said "PASS" but run-webkit-tests reported it
failed).

[haraken, 2016/09/23 01:50:34]

Hmm, this might be problematic.

SetVerbose(true) is needed to synchronously report the exception on the devtool
console. If we don't have SetVerbose(true), the exception won't be reported to
the devtool console until the next V8 function is fired.

[bashi, 2016/09/23 01:58:32]

What's a solution then? Also, why don't we always call SetVerbose(true)? It
seems there are a lot of TryCatch which we don't call SetVerbose().

-
     if (V8ScriptRunner::callFunction(m_callback.newLocal(scriptState->isolate()), scriptState->getExecutionContext(), scriptState->context()->Global(), {{arguments | length}}, argv, scriptState->isolate()).ToLocal(&v8ReturnValue))
     {
         {% if return_value %}
         {{v8_value_to_local_cpp_value(return_value) | indent(8)}}
         returnValue = cppValue;
         {% endif %}
         return true;
     }
+    DCHECK(exceptionCatcher.HasCaught());
+    exceptionState.rethrowV8Exception(exceptionCatcher.Exception());
     return false;
 }
 
 } // namespace blink
 
 {% endfilter %}{# format_blink_cpp_source_code #}