Replace ASSERT with DCHECK in core/

third_party/WebKit/Source/core/timing/SharedWorkerPerformance.cpp

Index: third_party/WebKit/Source/core/timing/SharedWorkerPerformance.cpp
diff --git a/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.cpp b/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.cpp
index 9187132e442dd8dc3eb7a8633ba38388b8f101ca..24c0dffe984b13b2340075c1ae13ac1fbcee4de0 100644
--- a/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.cpp
+++ b/third_party/WebKit/Source/core/timing/SharedWorkerPerformance.cpp
@@ -65,8 +65,8 @@ double SharedWorkerPerformance::workerStart(ScriptState* script_state,
 
 double SharedWorkerPerformance::GetWorkerStart(ExecutionContext* context,
                                                SharedWorker&) const {
-  ASSERT(context);
-  ASSERT(context->IsDocument());
+  DCHECK(context);
+  DCHECK(context->IsDocument());
   Document* document = ToDocument(context);
   if (!document->Loader())
     return 0;