Add a full Blimp integration test.

blimp/engine/browser_tests/waitable_content_pump.cc

Index: blimp/engine/browser_tests/waitable_content_pump.cc
diff --git a/blimp/engine/browser_tests/waitable_content_pump.cc b/blimp/engine/browser_tests/waitable_content_pump.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2b2f03ff707b5b4a873c9c335ee04ce5e59ca0d1
--- /dev/null
+++ b/blimp/engine/browser_tests/waitable_content_pump.cc
@@ -0,0 +1,32 @@
+// 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 "blimp/engine/browser_tests/waitable_content_pump.h"
+
+#include "content/public/browser/browser_thread.h"
+#include "content/public/test/test_utils.h"
+
+namespace blimp {
+
+WaitableContentPump::WaitableContentPump()
+    : event_(base::WaitableEvent::ResetPolicy::MANUAL,
+             base::WaitableEvent::InitialState::NOT_SIGNALED) {}
+
+WaitableContentPump::~WaitableContentPump() = default;
+
+// static
+void WaitableContentPump::WaitFor(base::WaitableEvent* event) {
+  while (!event->IsSignaled()) {
+    content::RunAllPendingInMessageLoop(content::BrowserThread::UI);
+    content::RunAllPendingInMessageLoop(content::BrowserThread::IO);
+    content::RunAllPendingInMessageLoop(content::BrowserThread::FILE);
+  }
+  event->Reset();
+}
+
+void WaitableContentPump::Wait() {
+  WaitableContentPump::WaitFor(&event_);
+}
+
+}  // namespace blimp