Turn a bunch of ASSERTs into graceful failures when compiling listeners

Source/bindings/core/v8/V8LazyEventListener.cpp

Index: Source/bindings/core/v8/V8LazyEventListener.cpp
diff --git a/Source/bindings/core/v8/V8LazyEventListener.cpp b/Source/bindings/core/v8/V8LazyEventListener.cpp
index fd8ee45989db8cca124171dffbd93e03d318cb06..1e4b11d74e758b39f3e49717e16d484d0fbc16d6 100644
--- a/Source/bindings/core/v8/V8LazyEventListener.cpp
+++ b/Source/bindings/core/v8/V8LazyEventListener.cpp
@@ -120,7 +120,10 @@ void V8LazyEventListener::prepareListenerObject(ExecutionContext* executionConte
     if (!scriptState->contextIsValid())
         return;
 
-    if (executionContext->isDocument() && !toDocument(executionContext)->allowInlineEventHandlers(m_node, this, m_sourceURL, m_position.m_line)) {
+    if (!executionContext->isDocument())
+        return;
+
+    if (!toDocument(executionContext)->allowInlineEventHandlers(m_node, this, m_sourceURL, m_position.m_line)) {
         clearListenerObject();
         return;
     }
@@ -128,8 +131,6 @@ void V8LazyEventListener::prepareListenerObject(ExecutionContext* executionConte
     if (hasExistingListenerObject())
         return;
 
-    ASSERT(executionContext->isDocument());
-
     ScriptState::Scope scope(scriptState);
     String listenerSource =  InspectorInstrumentation::preprocessEventListener(toDocument(executionContext)->frame(), m_code, m_sourceURL, m_functionName);
 
@@ -166,7 +167,8 @@ void V8LazyEventListener::prepareListenerObject(ExecutionContext* executionConte
         return;
 
     // Call the outer function to get the inner function.
-    ASSERT(result->IsFunction());
+    if (!result->IsFunction())
+        return;
     v8::Local<v8::Function> intermediateFunction = result.As<v8::Function>();
 
     HTMLFormElement* formElement = 0;