Use high precision timestamp for Event.timestamp

third_party/WebKit/Source/core/testing/Internals.cpp

Index: third_party/WebKit/Source/core/testing/Internals.cpp
diff --git a/third_party/WebKit/Source/core/testing/Internals.cpp b/third_party/WebKit/Source/core/testing/Internals.cpp
index a0e6f039bfb7dc6b99193ca32ac2f83e817f0ccf..ecea010c85b50f99c9a3e50f694864faa099e1da 100644
--- a/third_party/WebKit/Source/core/testing/Internals.cpp
+++ b/third_party/WebKit/Source/core/testing/Internals.cpp
@@ -105,6 +105,7 @@
 #include "core/layout/LayoutView.h"
 #include "core/layout/compositing/CompositedDeprecatedPaintLayerMapping.h"
 #include "core/layout/compositing/DeprecatedPaintLayerCompositor.h"
+#include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/HistoryItem.h"
 #include "core/page/ChromeClient.h"
@@ -2546,4 +2547,15 @@ void Internals::forceRestrictIFramePermissions()
     RuntimeEnabledFeatures::setRestrictIFramePermissionsEnabled(true);
 }
 
+double Internals::monotonicTimeToZeroBasedDocumentTime(double platformTime, ExceptionState& exceptionState)
+{
+    Document* document = contextDocument();
+    if (!document) {
+        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
+        return 0;
+    }
+
+    return document->loader()->timing().monotonicTimeToZeroBasedDocumentTime(platformTime);
+}
+
 } // namespace blink