[sensors] Fix flakiness in generic sensors tests

third_party/WebKit/Source/modules/sensor/SensorProviderProxy.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 "modules/sensor/SensorProviderProxy.h"
 
 #include "modules/sensor/SensorProxy.h"
 #include "modules/sensor/SensorReading.h"
 #include "platform/mojo/MojoHelper.h"
 #include "public/platform/InterfaceProvider.h"
 #include "public/platform/Platform.h"
 
 namespace blink {
 
 // SensorProviderProxy
 SensorProviderProxy::SensorProviderProxy(LocalFrame* frame) {
+  initialize(frame);
+}
+
+void SensorProviderProxy::initialize(LocalFrame* frame) {
+  DCHECK(!isInitialized());
+
   frame->interfaceProvider()->getInterface(mojo::GetProxy(&m_sensorProvider));
   m_sensorProvider.set_connection_error_handler(convertToBaseCallback(
       WTF::bind(&SensorProviderProxy::onSensorProviderConnectionError,
                 wrapWeakPersistent(this))));
 }
 
 const char* SensorProviderProxy::supplementName() {
   return "SensorProvider";
 }
 
+// static
 SensorProviderProxy* SensorProviderProxy::from(LocalFrame* frame) {
   DCHECK(frame);
-  SensorProviderProxy* result = static_cast<SensorProviderProxy*>(
+  SensorProviderProxy* providerProxy = static_cast<SensorProviderProxy*>(
       Supplement<LocalFrame>::from(*frame, supplementName()));
-  if (!result) {
-    result = new SensorProviderProxy(frame);
-    Supplement<LocalFrame>::provideTo(*frame, supplementName(), result);
+  if (!providerProxy) {
+    providerProxy = new SensorProviderProxy(frame);
+    Supplement<LocalFrame>::provideTo(*frame, supplementName(), providerProxy);
   }
-  return result;
+
+  if (!providerProxy->isInitialized())
+    providerProxy->initialize(frame);
+
+  return providerProxy;
 }
 
 SensorProviderProxy::~SensorProviderProxy() {}
 
 DEFINE_TRACE(SensorProviderProxy) {
   visitor->trace(m_sensorProxies);
   Supplement<LocalFrame>::trace(visitor);
 }
 
 SensorProxy* SensorProviderProxy::createSensorProxy(
@@ skipping 25 matching lines @@
     // TODO(rockot): Clean this up once renderer shutdown sequence is fixed.
     return;
   }
 
   m_sensorProvider.reset();
   for (SensorProxy* sensor : m_sensorProxies)
     sensor->handleSensorError();
 }
 
 }  // namespace blink