batteryservice: Remove remnants of CAF's HVDCP changes

Commit ce521ee removed the usage
of isHvdcpPresent(), but did not remove the function itself.

Remove isHvdcpPresent() as clean-up.

This essentially reverts the rest of the following commits:
64deb44 batteryservice: Avoid exception if device doesn't support HVDCP
4df4f53 batteryservice: add support for charger led blinking

Change-Id: Ie39c11ee9811f6af84a55ed85b72123cc449c735

Author: zwliew

services/core/java/com/android/server/BatteryService.java

@@ -58,10 +58,6 @@
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.FileOutputStream;
-import java.io.FileReader;
-import java.io.BufferedInputStream;
-import java.io.BufferedReader;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
 
@@ -1056,33 +1052,6 @@ public Led(Context context, LightsManager lights) {
                     org.cyanogenmod.platform.internal.R.bool.config_useSegmentedBatteryLed);
         }
 
-        private boolean isHvdcpPresent() {
-            File mChargerTypeFile = new File("/sys/class/power_supply/usb/type");
-            FileReader fileReader;
-            BufferedReader br;
-            String type;
-            boolean ret = false;
-
-            if (!mChargerTypeFile.exists()) {
-                // Device does not support HVDCP
-                return ret;
-            }
-
-            try {
-                fileReader = new FileReader(mChargerTypeFile);
-                br = new BufferedReader(fileReader);
-                type =  br.readLine();
-                if (type.regionMatches(true, 0, "USB_HVDCP", 0, 9))
-                    ret = true;
-                br.close();
-                fileReader.close();
-            } catch (IOException e) {
-                Slog.e(TAG, "Failure in reading charger type", e);
-            }
-
-            return ret;
-        }
-
         /**
          * Synchronize on BatteryService.
          */