Refactor OS_LINUX preprocessor directive for LaCrOS effort.

Currently, ChromeOS defines the OS_LINUX directive as well as
OS_CHROMEOS.  We're working to separate these two, so we're
making the fact that OS_LINUX == OS_LINUX || OS_CHROMEOS
explicit.

This is changes for /services/device/generic_sensor

This CL was uploaded by git cl split.

R=timvolodine@chromium.org

Bug: 1110266
Change-Id: I460f572b6271240ae68a867b8059894fac34b583
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2371299
Auto-Submit: Sean McAllister <smcallis@google.com>
Reviewed-by: Tim Volodine <timvolodine@chromium.org>
Commit-Queue: Tim Volodine <timvolodine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801021}

services/device/generic_sensor/platform_sensor_provider.cc

@@ -15,7 +15,7 @@
 #include "services/device/generic_sensor/platform_sensor_provider_win.h"
 #include "services/device/generic_sensor/platform_sensor_provider_winrt.h"
 #include "services/device/public/cpp/device_features.h"
-#elif defined(OS_LINUX) && defined(USE_UDEV)
+#elif (defined(OS_LINUX) || defined(OS_CHROMEOS)) && defined(USE_UDEV)
 #include "services/device/generic_sensor/platform_sensor_provider_linux.h"
 #endif
 
@@ -33,7 +33,7 @@ std::unique_ptr<PlatformSensorProvider> PlatformSensorProvider::Create() {
   } else {
     return std::make_unique<PlatformSensorProviderWin>();
   }
-#elif defined(OS_LINUX) && defined(USE_UDEV)
+#elif (defined(OS_LINUX) || defined(OS_CHROMEOS)) && defined(USE_UDEV)
   return std::make_unique<PlatformSensorProviderLinux>();
 #else
   return nullptr;