Always reset touch action at the beginning of a new gesture sequence

content/browser/renderer_host/input/web_touch_event_traits.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/renderer_host/input/web_touch_event_traits.h"
+
+#include "base/logging.h"
+
+using blink::WebInputEvent;
+using blink::WebTouchEvent;
+
+namespace content {
+
+bool WebTouchEventTraits::IsTouchSequenceStart(const WebTouchEvent& event) {
+  if (event.type != WebInputEvent::TouchStart)
+    return false;
+  DCHECK(event.touchesLength);
+  if (!event.touchesLength)
+    return false;
+  for (size_t i = 0; i < event.touchesLength; i++) {
+    if (event.touches[i].state != blink::WebTouchPoint::StatePressed)
+      return false;
+  }
+  return true;
+}
+
+}  // namespace content