Use chromeos accelerometer reader and support only lid accelerometer.

chromeos/accelerometer/accelerometer_reader.h

Index: chromeos/accelerometer/accelerometer_reader.h
diff --git a/chromeos/accelerometer/accelerometer_reader.h b/chromeos/accelerometer/accelerometer_reader.h
index c3c4efd7b9110662f76d1eef67bc6e97d0cd8045..a66b12c5828b19f4e51ea59b4b53c61200be70f9 100644
--- a/chromeos/accelerometer/accelerometer_reader.h
+++ b/chromeos/accelerometer/accelerometer_reader.h
@@ -5,8 +5,6 @@
 #ifndef CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_
 #define CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_
 
-#include <vector>
-
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
@@ -28,12 +26,20 @@ class CHROMEOS_EXPORT AccelerometerReader {
     ConfigurationData();
     ~ConfigurationData();
 
-    // Scale of accelerometers (i.e. raw value * 1.0f / scale = G's).
-    unsigned int base_scale;
-    unsigned int lid_scale;
+    // Number of accelerometers on device.
+    size_t count;
+
+    // Length of accelerometer updates.
+    size_t length;
+
+    // Which accelerometers are present on device.
+    bool has[ui::ACCELEROMETER_SOURCE_COUNT];
+
+    // Scale of accelerometers (i.e. raw value * scale = m/s^2).
+    float scale[ui::ACCELEROMETER_SOURCE_COUNT][3];
 
     // Index of each accelerometer axis in data stream.
-    std::vector<unsigned int> index;
+    int index[ui::ACCELEROMETER_SOURCE_COUNT][3];
   };
   typedef base::RefCountedData<ConfigurationData> Configuration;
   typedef base::RefCountedData<char[12]> Reading;