Split the constructor of ThreadableLoader into two methods (ctor and start())

third_party/WebKit/Source/modules/fetch/FetchManager.cpp

Index: third_party/WebKit/Source/modules/fetch/FetchManager.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/FetchManager.cpp b/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
index 6d563050f642adf9cc2ad430112cfbb30c7c561e..06e78f557d5bb8c3e8de05eb1e7aa3bff0853d0c 100644
--- a/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
+++ b/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
@@ -609,9 +609,8 @@ void FetchManager::Loader::performHTTPFetch(bool corsFlag, bool corsPreflightFla
         break;
     }
     InspectorInstrumentation::willStartFetch(executionContext(), this);
-    m_loader = ThreadableLoader::create(*executionContext(), this, request, threadableLoaderOptions, resourceLoaderOptions);
-    if (!m_loader)
-        performNetworkError("Can't create ThreadableLoader");
+    m_loader = ThreadableLoader::create(*executionContext(), this, threadableLoaderOptions, resourceLoaderOptions);
+    m_loader->start(request);
 }
 
 // performDataFetch() is almost the same as performHTTPFetch(), except for:
@@ -644,9 +643,8 @@ void FetchManager::Loader::performDataFetch()
     threadableLoaderOptions.crossOriginRequestPolicy = AllowCrossOriginRequests;
 
     InspectorInstrumentation::willStartFetch(executionContext(), this);
-    m_loader = ThreadableLoader::create(*executionContext(), this, request, threadableLoaderOptions, resourceLoaderOptions);
-    if (!m_loader)
-        performNetworkError("Can't create ThreadableLoader");
+    m_loader = ThreadableLoader::create(*executionContext(), this, threadableLoaderOptions, resourceLoaderOptions);
+    m_loader->start(request);
 }
 
 void FetchManager::Loader::failed(const String& message)