Fix "unused variable" warnings.

content/browser/device_sensors/data_fetcher_shared_memory_default.cc

 // Copyright 2014 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 "content/browser/device_sensors/data_fetcher_shared_memory.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 
 namespace {
@@ skipping 25 matching lines @@
   buffer->seqlock.WriteBegin();
   buffer->data.value = lux;
   buffer->seqlock.WriteEnd();
   return true;
 }
 
 }  // namespace
 
 namespace content {
 
-DataFetcherSharedMemory::DataFetcherSharedMemory()
-    : motion_buffer_(nullptr),
-      orientation_buffer_(nullptr),
-      orientation_absolute_buffer_(nullptr),
-      light_buffer_(nullptr) {
-}
+DataFetcherSharedMemory::DataFetcherSharedMemory() {}
 
 DataFetcherSharedMemory::~DataFetcherSharedMemory() {
 }
 
 bool DataFetcherSharedMemory::Start(ConsumerType consumer_type, void* buffer) {
   DCHECK(buffer);
 
   switch (consumer_type) {
     case CONSUMER_TYPE_MOTION:
       motion_buffer_ = static_cast<DeviceMotionHardwareBuffer*>(buffer);
@@ skipping 29 matching lines @@
       return SetOrientationBuffer(orientation_absolute_buffer_, false);
     case CONSUMER_TYPE_LIGHT:
       return SetLightBuffer(light_buffer_, -1);
     default:
       NOTREACHED();
   }
   return false;
 }
 
 }  // namespace content