[Sensors] Consider maximum supported frequency

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/frame/LocalFrame.h"
 #include "modules/sensor/SensorProviderProxy.h"
 #include "platform/mojo/MojoHelper.h"
 #include "public/platform/Platform.h"
 
 using namespace device::mojom::blink;
 
 namespace blink {
 
 SensorProxy::SensorProxy(SensorType sensorType, SensorProviderProxy* provider)
     : m_type(sensorType),
       m_mode(ReportingMode::CONTINUOUS),
       m_provider(provider),
       m_clientBinding(this),
       m_state(SensorProxy::Uninitialized),
       m_reading(),
-      m_suspended(false) {}
+      m_suspended(false),
+      m_maximumFrequency(0.0) {}
 
 SensorProxy::~SensorProxy() {}
 
 void SensorProxy::dispose() {
   m_clientBinding.Close();
 }
 
 DEFINE_TRACE(SensorProxy) {
   visitor->trace(m_observers);
   visitor->trace(m_provider);
@@ skipping 57 matching lines @@
   m_sensor->Resume();
   m_suspended = false;
 }
 
 const device::mojom::blink::SensorConfiguration* SensorProxy::defaultConfig()
     const {
   DCHECK(isInitialized());
   return m_defaultConfig.get();
 }
 
+double SensorProxy::maximumFrequency() const {
+  return m_maximumFrequency;
+}
+
 void SensorProxy::updateInternalReading() {
   DCHECK(isInitialized());
   int readAttempts = 0;
   const int kMaxReadAttemptsCount = 10;
   while (!tryReadFromBuffer()) {
     if (++readAttempts == kMaxReadAttemptsCount) {
       handleSensorError();
       return;
     }
   }
@@ skipping 50 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_maximumFrequency = params->maximum_frequency;
+  DCHECK(m_maximumFrequency <= SensorConfiguration::kMaxAllowedFrequency);
+
   auto errorCallback =
       WTF::bind(&SensorProxy::handleSensorError, wrapWeakPersistent(this),
                 UnknownError, String("Internal error"), String());
   m_sensor.set_connection_error_handler(
       convertToBaseCallback(std::move(errorCallback)));
 
   m_state = Initialized;
   for (Observer* observer : m_observers)
     observer->onSensorInitialized();
 }
 
 bool SensorProxy::tryReadFromBuffer() {
   DCHECK(isInitialized());
   const ReadingBuffer* buffer =
       static_cast<const ReadingBuffer*>(m_sharedBuffer.get());
   const device::OneWriterSeqLock& seqlock = buffer->seqlock.value();
   auto version = seqlock.ReadBegin();
   auto reading = buffer->reading;
   if (seqlock.ReadRetry(version))
     return false;
   m_reading = reading;
   return true;
 }
 
 }  // namespace blink