Fix ParsableByteArrayTest.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=112693523

library/src/androidTest/java/com/google/android/exoplayer/util/ParsableByteArrayTest.java

@@ -346,6 +346,13 @@ public class ParsableByteArrayTest extends TestCase {
     assertEquals(data.length, byteArray.getPosition());
   }
 
+  public void testReadAsciiString() {
+    byte[] data = new byte[] {'t', 'e', 's', 't'};
+    ParsableByteArray testArray = new ParsableByteArray(data);
+    assertEquals("test", testArray.readString(data.length, Charset.forName("US-ASCII")));
+    assertEquals(data.length, testArray.getPosition());
+  }
+
   public void testReadStringOutOfBoundsDoesNotMovePosition() {
     byte[] data = {
         (byte) 0xC3, (byte) 0xA4, (byte) 0x20
@@ -416,11 +423,4 @@ public class ParsableByteArrayTest extends TestCase {
     assertNull(parser.readLine());
   }
 
-  public void testReadString() {
-    byte[] bytes = new byte[] {'t', 'e', 's', 't'};
-    ParsableByteArray testArray = new ParsableByteArray(bytes);
-    assertEquals("test", testArray.readString(bytes.length, Charset.forName("UTF-8")));
-    assertEquals(bytes.length, testArray.getPosition());
-  }
-
 }

library/src/main/java/com/google/android/exoplayer/util/ParsableByteArray.java

@@ -310,13 +310,24 @@ public final class ParsableByteArray {
   /**
    * Reads the next {@code length} bytes as UTF-8 characters.
    *
-   * @param length the number of bytes to read.
-   * @return the UTF-8 {@code String} read.
+   * @param length The number of bytes to read.
+   * @return The string encoded by the bytes.
    */
   public String readString(int length) {
-    String utf8String = new String(data, position, length);
+    return readString(length, Charset.defaultCharset());
+  }
+
+  /**
+   * Reads the next {@code length} bytes as characters in the specified {@link Charset}.
+   *
+   * @param length The number of bytes to read.
+   * @param charset The character set of the encoded characters.
+   * @return The string encoded by the bytes in the specified character set.
+   */
+  public String readString(int length, Charset charset) {
+    String result = new String(data, position, length, charset);
     position += length;
-    return utf8String;
+    return result;
   }
 
   /**
@@ -359,17 +370,4 @@ public final class ParsableByteArray {
     return line;
   }
 
-  /**
-   * Reads the next {@code bytes} bytes as characters in the specified {@link Charset}.
-   *
-   * @param bytes The number of bytes to read.
-   * @param charset The character set of the encoded characters.
-   * @return The string encoded by the bytes in the specified character set.
-   */
-  public String readString(int bytes, Charset charset) {
-    String result = new String(data, position, bytes, charset);
-    position += bytes;
-    return result;
-  }
-
 }