[Sensors] Clamp given sampling frequency to the minimum supported one

third_party/WebKit/Source/modules/sensor/SensorProxy.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/SensorProxy.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/LocalFrame.h"
 #include "modules/sensor/SensorProviderProxy.h"
 #include "modules/sensor/SensorReadingUpdater.h"
 #include "platform/mojo/MojoHelper.h"
 #include "public/platform/Platform.h"
 
 using namespace device::mojom::blink;
 
 namespace blink {
 
 SensorProxy::SensorProxy(SensorType sensorType,
                          SensorProviderProxy* provider,
                          Page* page)
     : PageVisibilityObserver(page),
       m_type(sensorType),
       m_mode(ReportingMode::CONTINUOUS),
       m_provider(provider),
       m_clientBinding(this),
       m_state(SensorProxy::Uninitialized),
-      m_suspended(false),
-      m_maximumFrequency(0.0) {}
+      m_suspended(false) {}
 
 SensorProxy::~SensorProxy() {}
 
 void SensorProxy::dispose() {
   m_clientBinding.Close();
 }
 
 DEFINE_TRACE(SensorProxy) {
   visitor->trace(m_readingUpdater);
   visitor->trace(m_observers);
@@ skipping 165 matching lines @@
 
   m_sharedBufferHandle = std::move(params->memory);
   DCHECK(!m_sharedBuffer);
   m_sharedBuffer =
       m_sharedBufferHandle->MapAtOffset(kReadBufferSize, params->buffer_offset);
 
   if (!m_sharedBuffer) {
     handleSensorError();
     return;
   }
+  m_frequencyLimits.first = params->minimum_frequency;
+  m_frequencyLimits.second = params->maximum_frequency;
 
-  m_maximumFrequency = params->maximum_frequency;
-  DCHECK(m_maximumFrequency <= SensorConfiguration::kMaxAllowedFrequency);
+  DCHECK_GT(m_frequencyLimits.first, 0.0);
+  DCHECK_GE(m_frequencyLimits.second, m_frequencyLimits.first);
+  constexpr double kMaxAllowedFrequency =
+      SensorConfiguration::kMaxAllowedFrequency;
+  DCHECK_GE(kMaxAllowedFrequency, m_frequencyLimits.second);
 
   auto errorCallback =
       WTF::bind(&SensorProxy::handleSensorError, wrapWeakPersistent(this));
   m_sensor.set_connection_error_handler(
       convertToBaseCallback(std::move(errorCallback)));
 
   m_readingUpdater = SensorReadingUpdater::create(this, m_mode);
 
   m_state = Initialized;
 
@@ skipping 36 matching lines @@
   const device::OneWriterSeqLock& seqlock = buffer->seqlock.value();
   auto version = seqlock.ReadBegin();
   auto readingData = buffer->reading;
   if (seqlock.ReadRetry(version))
     return false;
   result = readingData;
   return true;
 }
 
 }  // namespace blink