Adds enableVirtualTime and setVirtualTimePolicy To Emulation domain.

third_party/WebKit/Source/platform/WebViewScheduler.cpp

+// Copyright 2016 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 "public/platform/WebViewScheduler.h"
+
+namespace blink {
+
+WebViewScheduler::WebViewScheduler()

[Sami, 2016/07/01 14:46:30]

Let's avoid forking WebViewScheduler and WebViewSchedulerImpl like this and
instead implement this in the latter. We're in the about move
WebViewSchedulerImpl to Blink soon anyway so I think that will simplify the
transition.

[alex clarke (OOO till 29th), 2016/07/01 15:53:23]

Done.

+    : m_pendingResourceLoadCount(0)
+    , m_virtualTimePolicy(VirtualTimePolicy::ADVANCE) { }
+
+WebViewScheduler::~WebViewScheduler() { }
+
+void WebViewScheduler::incrementPendingResourceLoadCount()
+{
+    m_pendingResourceLoadCount++;
+
+    if (m_virtualTimePolicy != VirtualTimePolicy::PAUSE_IF_NETWORK_FETCHES_PENDING)
+        return;
+
+    if (m_pendingResourceLoadCount == 1)
+        setAllowVirtualTimeToAdvance(false);
+}
+
+void WebViewScheduler::decrementPendingResourceLoadCount()
+{
+    m_pendingResourceLoadCount--;
+    DCHECK_GE(m_pendingResourceLoadCount, 0);
+
+    if (m_virtualTimePolicy != VirtualTimePolicy::PAUSE_IF_NETWORK_FETCHES_PENDING)
+        return;
+
+    if (m_pendingResourceLoadCount == 0)
+        setAllowVirtualTimeToAdvance(true);
+}
+
+void WebViewScheduler::setVirtualTimePolicy(VirtualTimePolicy policy)
+{
+    m_virtualTimePolicy = policy;
+
+    switch (m_virtualTimePolicy) {
+    case VirtualTimePolicy::ADVANCE:
+        setAllowVirtualTimeToAdvance(true);
+        break;
+
+    case VirtualTimePolicy::PAUSE:
+        setAllowVirtualTimeToAdvance(false);
+        break;
+
+    case VirtualTimePolicy::PAUSE_IF_NETWORK_FETCHES_PENDING:
+        setAllowVirtualTimeToAdvance(m_pendingResourceLoadCount == 0);
+        break;
+    }
+}
+
+} // namespace blink