Reland: Do not initialize v8::Context on |ScriptController::updateDocument|.

Source/core/testing/v8/WebCoreTestSupport.cpp

Index: Source/core/testing/v8/WebCoreTestSupport.cpp
diff --git a/Source/core/testing/v8/WebCoreTestSupport.cpp b/Source/core/testing/v8/WebCoreTestSupport.cpp
index e0553ab5f7c7f5c6d795e93db179c9cf4cb1d91f..69ea28d3902de54d80f966c94dfb8674ff380916 100644
--- a/Source/core/testing/v8/WebCoreTestSupport.cpp
+++ b/Source/core/testing/v8/WebCoreTestSupport.cpp
@@ -41,6 +41,10 @@ namespace WebCoreTestSupport {
 
 void injectInternalsObject(v8::Local<v8::Context> context)
 {
+    // This can happen if no JavaScript was used in the main frame.
+    if (context.IsEmpty())
+        return;
+
     v8::Context::Scope contextScope(context);
     v8::HandleScope scope(context->GetIsolate());
     ExecutionContext* scriptContext = currentExecutionContext(context->GetIsolate());