Add support for audio device selection in AppRTCDemo.

Summary:

- Creates a list of available (possible to select) audio devices.
- Automatically selects (routes audio) the "best/default" audio device.
- If possible, starts a proximity sensor that will switch between headset earpiece and speaker phone based on how close the a person's ear the mobile device is held.

TBR=glaznev

BUG=4103,4109

Review URL: https://webrtc-codereview.appspot.com/31239004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7978 4adac7df-926f-26a2-2b94-8c16560cd09d

talk/examples/android/src/org/appspot/apprtc/util/AppRTCUtils.java

@@ -0,0 +1,82 @@
+/*
+ * libjingle
+ * Copyright 2014, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.appspot.apprtc.util;
+
+import android.os.Build;
+import android.util.Log;
+import java.lang.Thread;
+
+public final class AppRTCUtils {
+
+  private AppRTCUtils() {
+  }
+
+  /**
+   * NonThreadSafe is a helper class used to help verify that methods of a
+   * class are called from the same thread.
+   */
+  public static class NonThreadSafe {
+    private final Long threadId;
+
+    public NonThreadSafe() {
+      // Store thread ID of the creating thread.
+      threadId = Thread.currentThread().getId();
+    }
+
+   /** Checks if the method is called on the valid/creating thread. */
+    public boolean calledOnValidThread() {
+       return threadId.equals(Thread.currentThread().getId());
+    }
+  }
+
+  /** Helper method which throws an exception  when an assertion has failed. */
+  public static void assertIsTrue(boolean condition) {
+    if (!condition) {
+      throw new AssertionError("Expected condition to be true");
+    }
+  }
+
+  /** Helper method for building a string of thread information.*/
+  public static String getThreadInfo() {
+    return "@[name=" + Thread.currentThread().getName()
+        + ", id=" + Thread.currentThread().getId() + "]";
+  }
+
+  /** Information about the current build, taken from system properties. */
+  public static void logDeviceInfo(String tag) {
+    Log.d(tag, "Android SDK: " + Build.VERSION.SDK_INT + ", "
+        + "Release: " + Build.VERSION.RELEASE + ", "
+        + "Brand: " + Build.BRAND + ", "
+        + "Device: " + Build.DEVICE + ", "
+        + "Id: " + Build.ID + ", "
+        + "Hardware: " + Build.HARDWARE + ", "
+        + "Manufacturer: " + Build.MANUFACTURER + ", "
+        + "Model: " + Build.MODEL + ", "
+        + "Product: " + Build.PRODUCT);
+  }
+}