When historyEntryRequiresUserGesture is enabled, exempt docs that have been committed for 5 seconds

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 43aaf0a8818e7d3dffa5b297bf1756910e408cac..7d1a15d2fdb92e8ac60ec11186a3e4ea0269a116 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -282,6 +282,10 @@ static const unsigned cMaxWriteRecursionDepth = 21;
 // adequate, but a little high for dual G5s. :)
 static const int cLayoutScheduleThreshold = 250;
 
+// After a document has been committed for this time, it can create a history
+// entry even if the user hasn't interacted with the document.
+static const int cElapsedTimeForHistoryEntryWithoutUserGestureMS = 5000;
+
 // DOM Level 2 says (letters added):
 //
 // a) Name start characters must have one of the categories Ll, Lu, Lo, Lt, Nl.
@@ -3189,6 +3193,21 @@ int Document::elapsedTime() const {
   return static_cast<int>((currentTime() - m_startTime) * 1000);
 }
 
+bool Document::canCreateHistoryEntry() const {
+  // TODO(japhet): This flag controls an intervention to require a user gesture
+  // or a long time on page in order for a content-initiated navigation to add
+  // an entry to the back/forward list. Removing the flag and making this the
+  // default will require updating a couple hundred tests that currently depend
+  // on creating history entries without user gestures. I'm waiting to update
+  // the tests until the feature is proven to minimize churn.
+  // https://bugs.chromium.org/p/chromium/issues/detail?id=638198
+  if (!m_frame->settings()->getHistoryEntryRequiresUserGesture())
+    return true;
+  if (m_frame->hasReceivedUserGesture())
+    return true;
+  return elapsedTime() >= cElapsedTimeForHistoryEntryWithoutUserGestureMS;
+}
+
 void Document::write(const SegmentedString& text,
                      Document* enteredDocument,
                      ExceptionState& exceptionState) {