Simplify invokeCallback() and support void return values for IDL callbacks

Source/bindings/v8/custom/V8CustomSQLStatementErrorCallback.cpp

Index: Source/bindings/v8/custom/V8CustomSQLStatementErrorCallback.cpp
diff --git a/Source/bindings/v8/custom/V8CustomSQLStatementErrorCallback.cpp b/Source/bindings/v8/custom/V8CustomSQLStatementErrorCallback.cpp
index 5a5aaf1ddad065321aab8c864509d57d23775c5d..fc597c110345da297a77e706a57a2381e2f72629 100644
--- a/Source/bindings/v8/custom/V8CustomSQLStatementErrorCallback.cpp
+++ b/Source/bindings/v8/custom/V8CustomSQLStatementErrorCallback.cpp
@@ -33,7 +33,7 @@
 
 #include "V8SQLError.h"
 #include "V8SQLTransaction.h"
-#include "bindings/v8/V8Callback.h"
+#include "bindings/v8/ScriptController.h"
 #include "core/dom/ExecutionContext.h"
 #include "wtf/Assertions.h"
 
@@ -66,12 +66,18 @@ bool V8SQLStatementErrorCallback::handleEvent(SQLTransaction* transaction, SQLEr
         errorHandle
     };
 
-    bool callbackReturnValue = false;
+    v8::TryCatch exceptionCatcher;
+    exceptionCatcher.SetVerbose(true);
+
+    v8::Handle<v8::Value> result = ScriptController::callFunction(executionContext(), m_callback.newLocal(isolate), isolate->GetCurrentContext()->Global(), 2, argv, isolate);

[haraken, 2013/12/11 00:54:30]

I'm curious why you changed invokeCallback() to callFunction().

[adamk, 2013/12/11 01:05:48]

This allowed me to get rid of the callbackReturnValue argument to
invokeCallback(), as none of the other callers looked at it.

+
+    // FIXME: This comment doesn't make much sense given what the code is actually doing.

[haraken, 2013/12/11 00:54:30]

Yeah, probably we can remove the comment.

[adamk, 2013/12/11 01:05:48]

I'm going to leave it for posterity, I think; there's lots of callback stuff
that just seems wrong in WebSQL, and I think this comment might be part of that
trail of breadcrumbs.

+    //
     // Step 6: If the error callback returns false, then move on to the next
     // statement, if any, or onto the next overall step otherwise. Otherwise,
     // the error callback did not return false, or there was no error callback.
     // Jump to the last step in the overall steps.
-    return invokeCallback(m_callback.newLocal(isolate), 2, argv, callbackReturnValue, executionContext(), isolate) || callbackReturnValue;
+    return exceptionCatcher.HasCaught() || (!result.IsEmpty() && result->BooleanValue());
 }
 
 } // namespace WebCore