[Sensors] Add README.md files

third_party/WebKit/Source/modules/sensor/README.md

Index: third_party/WebKit/Source/modules/sensor/README.md
diff --git a/third_party/WebKit/Source/modules/sensor/README.md b/third_party/WebKit/Source/modules/sensor/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..4f076da241fad167b684d8fa794d007c7eeeccfa
--- /dev/null
+++ b/third_party/WebKit/Source/modules/sensor/README.md
@@ -0,0 +1,25 @@
+# Generic Sensor
+
+`third_party/WebKit/Source/modules/sensor` implements the following concrete
+sensor intrefaces based on the [Generic Sensor API]
+(https://w3c.github.io/sensors):
+1. [Ambient Light Sensor] (https://w3c.github.io/ambient-light)
+1. [Accelerometer] (https://w3c.github.io/accelerometer)
+1. [Gyroscope] (https://w3c.github.io/gyroscope)
+1. [Magnetometer] (https://w3c.github.io/magnetometer)
+1. [Absolute Orientation Sensor] (https://w3c.github.io/orientation-sensor)
+
+The platform-specific parts of the implementation are located in
+`device/generic_sensor`.
+
+
+## Testing
+
+Sensors layout tests are located in `LayoutTests/sensor`.
+
+Sensors browser tests are located in `content/test/data/generic_sensor`.
+
+
+## Design Documents
+
+Please refer to the [design documentation](https://docs.google.com/document/d/1Ml65ZdW5AgIsZTszk4mD_ohr40pcrdVFOIf0ZtWxDv0) for more details.