Export RenderWidgetHostViewAura and sensors::Provider to fix component build.

content/browser/sensors/sensors_provider.h

Index: content/browser/sensors/sensors_provider.h
diff --git a/content/browser/sensors/sensors_provider.h b/content/browser/sensors/sensors_provider.h
index 72bc15fd24fb441396ea9913a37250e04419734e..e647a4feebb49fa00d3f58f91d2e058a1ccd364d 100644
--- a/content/browser/sensors/sensors_provider.h
+++ b/content/browser/sensors/sensors_provider.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include "base/basictypes.h"
+#include "content/common/content_export.h"
 #include "content/common/sensors_listener.h"
 
 // The sensors API will unify various types of sensor data into a set of
@@ -22,7 +23,7 @@ namespace sensors {
 // TODO(cwolfe): Finish defining the initial set of channels and replace this
 // with the generic sensor provider.
 //
-class Provider {
+class CONTENT_EXPORT Provider {
  public:
   static Provider* GetInstance();