Revert "Soften the history.{push,replace}State throttling mechanism."

This reverts commit 1f637a1a.

Reason for revert: Part 2 of trying to revert history throttling changes to see if https://bugs.chromium.org/p/chromium/issues/detail?id=870861 improves.

Original change's description:
> Soften the history.{push,replace}State throttling mechanism.
> 
> johnme@ suggests a better way to handle it; let's do that.
> 
> Bug: 786211
> Change-Id: I446c70117451d2ef49ce13f5884ebb858d9ee392
> Reviewed-on: https://chromium-review.googlesource.com/1161400
> Commit-Queue: Chris Palmer <palmer@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#580455}

TBR=palmer@chromium.org,dcheng@chromium.org,kinuko@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 786211
Change-Id: Ia6a35add136361834c3afb40295b950c05cb9169
Reviewed-on: https://chromium-review.googlesource.com/1171709Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582434}

third_party/blink/renderer/core/frame/history.cc

@@ -148,28 +148,22 @@ bool History::ShouldThrottleStateObjectChanges() {
   if (!GetFrame()->GetSettings()->GetShouldThrottlePushState())
     return false;
 
-  if (state_flood_guard.tokens > 0) {
-    state_flood_guard.tokens--;
-    return false;
-  }
-
-  const auto now = TimeTicks::Now();
-  const TimeDelta elapsed = now - state_flood_guard.last_token_grant;
-  static constexpr base::TimeDelta kTimePerToken =
-      base::TimeDelta::FromMilliseconds(16);
-  static constexpr int kMaxTokens = 50;
-  // It is OK to truncate from int64_t to int here.
-  const int tokens_earned = std::min<int>(elapsed / kTimePerToken, kMaxTokens);
-
-  if (tokens_earned > 0) {
-    state_flood_guard.tokens = tokens_earned - 1;  // One consumed immediately.
-    state_flood_guard.last_token_grant = now;
-    return false;
+  const int kStateUpdateLimit = 50;
+
+  if (state_flood_guard.count > kStateUpdateLimit) {
+    static constexpr auto kStateUpdateLimitResetInterval =
+        TimeDelta::FromSeconds(10);
+    const auto now = CurrentTimeTicks();
+    if (now - state_flood_guard.last_updated > kStateUpdateLimitResetInterval) {
+      state_flood_guard.count = 0;
+      state_flood_guard.last_updated = now;
+      return false;
+    }
+    return true;
   }
 
-  // Drop this event (though ideally it would be delivered once there are tokens
-  // again, unless obsoleted by a subsequent state object change).
-  return true;
+  state_flood_guard.count++;
+  return false;
 }
 
 bool History::stateChanged() const {

third_party/blink/renderer/core/frame/history.h

@@ -107,8 +107,8 @@ class CORE_EXPORT History final : public ScriptWrappable,
 
   scoped_refptr<SerializedScriptValue> last_state_object_requested_;
   struct {
-    int tokens = 0;
-    TimeTicks last_token_grant;
+    int count;
+    TimeTicks last_updated;
   } state_flood_guard;
 };