Cache all chrome.loadTimes info before passing them to setters.

chrome/renderer/loadtimes_extension_bindings.cc

Index: chrome/renderer/loadtimes_extension_bindings.cc
diff --git a/chrome/renderer/loadtimes_extension_bindings.cc b/chrome/renderer/loadtimes_extension_bindings.cc
index 036c98064308cb465e0386bea6b540ae115774f2..692b80867db37c8c199d6b0494e9eba990864b7f 100644
--- a/chrome/renderer/loadtimes_extension_bindings.cc
+++ b/chrome/renderer/loadtimes_extension_bindings.cc
@@ -99,71 +99,73 @@ class LoadTimesExtensionWrapper : public v8::Extension {
 
   static void GetLoadTimes(const v8::FunctionCallbackInfo<v8::Value>& args) {
     WebLocalFrame* frame = WebLocalFrame::frameForCurrentContext();
-    if (frame) {
-      WebDataSource* data_source = frame->dataSource();
-      if (data_source) {
-        DocumentState* document_state =
-            DocumentState::FromDataSource(data_source);
-        v8::Isolate* isolate = args.GetIsolate();
-        v8::Local<v8::Object> load_times = v8::Object::New(isolate);
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "requestTime"),
-            v8::Number::New(isolate,
-                            document_state->request_time().ToDoubleT()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "startLoadTime"),
-            v8::Number::New(isolate,
-                            document_state->start_load_time().ToDoubleT()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "commitLoadTime"),
-            v8::Number::New(isolate,
-                            document_state->commit_load_time().ToDoubleT()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "finishDocumentLoadTime"),
-            v8::Number::New(
-                isolate,
-                document_state->finish_document_load_time().ToDoubleT()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "finishLoadTime"),
-            v8::Number::New(isolate,
-                            document_state->finish_load_time().ToDoubleT()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "firstPaintTime"),
-            v8::Number::New(isolate,
-                            document_state->first_paint_time().ToDoubleT()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "firstPaintAfterLoadTime"),
-            v8::Number::New(
-                isolate,
-                document_state->first_paint_after_load_time().ToDoubleT()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "navigationType"),
-            v8::String::NewFromUtf8(
-                isolate, GetNavigationType(data_source->navigationType())));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "wasFetchedViaSpdy"),
-            v8::Boolean::New(isolate, document_state->was_fetched_via_spdy()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "wasNpnNegotiated"),
-            v8::Boolean::New(isolate, document_state->was_npn_negotiated()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "npnNegotiatedProtocol"),
-            v8::String::NewFromUtf8(
-                isolate, document_state->npn_negotiated_protocol().c_str()));
-        load_times->Set(
-            v8::String::NewFromUtf8(isolate, "wasAlternateProtocolAvailable"),
-            v8::Boolean::New(
-                isolate, document_state->was_alternate_protocol_available()));
-        load_times->Set(v8::String::NewFromUtf8(isolate, "connectionInfo"),
-                        v8::String::NewFromUtf8(
-                            isolate,
-                            net::HttpResponseInfo::ConnectionInfoToString(
-                                document_state->connection_info()).c_str()));
-        args.GetReturnValue().Set(load_times);
-        return;
-      }
+    if (!frame) {
+      args.GetReturnValue().SetNull();
+      return;
     }
-    args.GetReturnValue().SetNull();
+    WebDataSource* data_source = frame->dataSource();
+    if (!data_source) {
+      args.GetReturnValue().SetNull();
+      return;
+    }
+    DocumentState* document_state = DocumentState::FromDataSource(data_source);
+    if (!document_state) {
+      args.GetReturnValue().SetNull();
+      return;
+    }
+    double request_time = document_state->request_time().ToDoubleT();
+    double start_load_time = document_state->start_load_time().ToDoubleT();
+    double commit_load_time = document_state->commit_load_time().ToDoubleT();
+    double finish_document_load_time =
+        document_state->finish_document_load_time().ToDoubleT();
+    double finish_load_time = document_state->finish_load_time().ToDoubleT();
+    double first_paint_time = document_state->first_paint_time().ToDoubleT();
+    double first_paint_after_load_time =
+        document_state->first_paint_after_load_time().ToDoubleT();
+    std::string navigation_type =
+        GetNavigationType(data_source->navigationType());
+    bool was_fetched_via_spdy = document_state->was_fetched_via_spdy();
+    bool was_npn_negotiated = document_state->was_npn_negotiated();
+    std::string npn_negotiated_protocol =
+        document_state->npn_negotiated_protocol();
+    bool was_alternate_protocol_available =
+        document_state->was_alternate_protocol_available();
+    std::string connection_info = net::HttpResponseInfo::ConnectionInfoToString(
+        document_state->connection_info());
+    // Important: |frame|, |data_source| and |document_state| should not be
+    // referred to below this line, as JS setters below can invalidate these
+    // pointers.
+    v8::Isolate* isolate = args.GetIsolate();
+    v8::Local<v8::Object> load_times = v8::Object::New(isolate);
+    load_times->Set(v8::String::NewFromUtf8(isolate, "requestTime"),
+                    v8::Number::New(isolate, request_time));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "startLoadTime"),
+                    v8::Number::New(isolate, start_load_time));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "commitLoadTime"),
+                    v8::Number::New(isolate, commit_load_time));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "finishDocumentLoadTime"),
+                    v8::Number::New(isolate, finish_document_load_time));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "finishLoadTime"),
+                    v8::Number::New(isolate, finish_load_time));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "firstPaintTime"),
+                    v8::Number::New(isolate, first_paint_time));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "firstPaintAfterLoadTime"),
+                    v8::Number::New(isolate, first_paint_after_load_time));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "navigationType"),
+                    v8::String::NewFromUtf8(isolate, navigation_type.c_str()));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "wasFetchedViaSpdy"),
+                    v8::Boolean::New(isolate, was_fetched_via_spdy));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "wasNpnNegotiated"),
+                    v8::Boolean::New(isolate, was_npn_negotiated));
+    load_times->Set(
+        v8::String::NewFromUtf8(isolate, "npnNegotiatedProtocol"),
+        v8::String::NewFromUtf8(isolate, npn_negotiated_protocol.c_str()));
+    load_times->Set(
+        v8::String::NewFromUtf8(isolate, "wasAlternateProtocolAvailable"),
+        v8::Boolean::New(isolate, was_alternate_protocol_available));
+    load_times->Set(v8::String::NewFromUtf8(isolate, "connectionInfo"),
+                    v8::String::NewFromUtf8(isolate, connection_info.c_str()));
+    args.GetReturnValue().Set(load_times);
   }
 
   static void GetCSI(const v8::FunctionCallbackInfo<v8::Value>& args) {