1 files changed, 47 insertions, 0 deletions
diff --git a/dom/ipc/CoalescedInputData.cpp b/dom/ipc/CoalescedInputData.cpp
new file mode 100644
index 0000000000..6336f86928
--- /dev/null
+++ b/dom/ipc/CoalescedInputData.cpp
@@ -0,0 +1,47 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsRefreshDriver.h"
+#include "BrowserChild.h"
+#include "CoalescedInputData.h"
+#include "mozilla/PresShell.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+void CoalescedInputFlusher::StartObserver() {
+  nsRefreshDriver* refreshDriver = GetRefreshDriver();
+  if (mRefreshDriver && mRefreshDriver == refreshDriver) {
+    // Nothing to do if we already added an observer and it's same refresh
+    // driver.
+    return;
+  }
+  RemoveObserver();
+  if (refreshDriver) {
+    mRefreshDriver = refreshDriver;
+    mRefreshDriver->AddRefreshObserver(this, FlushType::Event,
+                                       "Coalesced input move flusher");
+  }
+}
+
+CoalescedInputFlusher::CoalescedInputFlusher(BrowserChild* aBrowserChild)
+    : mBrowserChild(aBrowserChild) {}
+
+void CoalescedInputFlusher::RemoveObserver() {
+  if (mRefreshDriver) {
+    mRefreshDriver->RemoveRefreshObserver(this, FlushType::Event);
+    mRefreshDriver = nullptr;
+  }
+}
+
+CoalescedInputFlusher::~CoalescedInputFlusher() = default;
+
+nsRefreshDriver* CoalescedInputFlusher::GetRefreshDriver() {
+  if (PresShell* presShell = mBrowserChild->GetTopLevelPresShell()) {
+    return presShell->GetRefreshDriver();
+  }
+  return nullptr;
+}