Enable control over frame time in SimTests

third_party/WebKit/Source/web/tests/sim/SimCompositor.cpp

Index: third_party/WebKit/Source/web/tests/sim/SimCompositor.cpp
diff --git a/third_party/WebKit/Source/web/tests/sim/SimCompositor.cpp b/third_party/WebKit/Source/web/tests/sim/SimCompositor.cpp
index 23a105cd9670e131486ec65b5917a79e8cf10f9a..bb3a8ac2a24b5617c63d68310afa09ac73d69027 100644
--- a/third_party/WebKit/Source/web/tests/sim/SimCompositor.cpp
+++ b/third_party/WebKit/Source/web/tests/sim/SimCompositor.cpp
@@ -80,13 +80,17 @@ void SimCompositor::clearSelection() {
 }
 
 SimDisplayItemList SimCompositor::beginFrame() {
+  beginFrame(m_lastFrameTimeMonotonic + 0.016);
+}
+
+SimDisplayItemList SimCompositor::beginFrame(double timeInSeconds) {
   DCHECK(m_webViewImpl);
   DCHECK(!m_deferCommits);
   DCHECK(m_needsBeginFrame);
+  DCHECK_GT(m_lastFrameTimeMonotonic, timeInSeconds);
   m_needsBeginFrame = false;
 
-  // Always advance the time as if the compositor was running at 60fps.
-  m_lastFrameTimeMonotonic = monotonicallyIncreasingTime() + 0.016;
+  m_lastFrameTimeMonotonic = timeInSeconds;
 
   m_webViewImpl->beginFrame(m_lastFrameTimeMonotonic);
   m_webViewImpl->updateAllLifecyclePhases();