Update Android camera switch API to allow specifying a name

The current camera switch API sequentially cycles through each
camera name for each method invocation. This policy provides
reasonable behavior for devices with 2 or 3 cameras, but
presents challenges with devices that contain several cameras.
For example in a scenario where the current camera is oriented
on the same side as the next camera name, a developer would need to
call switchCamera multiple times to capture from a camera oriented on
a different side of the device.

This commit allows a developer to specify a camera name when switching
cameras. This flexibility allows developers to have more control over
which device they switch to in cases where a device contains several cameras.

Bug: webrtc:11261
Change-Id: I93d46d70b2c7cf735a411a4ef4f33e926bf3a5ea
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/165040
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30199}

sdk/android/instrumentationtests/src/org/webrtc/Camera1CapturerUsingByteBufferTest.java

@@ -114,6 +114,12 @@ public class Camera1CapturerUsingByteBufferTest {
     fixtures.switchCamera();
   }
 
+  @Test
+  @MediumTest
+  public void testSwitchVideoCapturerToSpecificCameraName() throws InterruptedException {
+    fixtures.switchCamera(true /* specifyCameraName */);
+  }
+
   @Test
   @MediumTest
   public void testCameraEvents() throws InterruptedException {

sdk/android/instrumentationtests/src/org/webrtc/Camera1CapturerUsingTextureTest.java

@@ -109,6 +109,12 @@ public class Camera1CapturerUsingTextureTest {
     fixtures.switchCamera();
   }
 
+  @Test
+  @MediumTest
+  public void testSwitchVideoCapturerToSpecificCameraName() throws InterruptedException {
+    fixtures.switchCamera(true /* specifyCameraName */);
+  }
+
   @Test
   @MediumTest
   public void testCameraEvents() throws InterruptedException {

sdk/android/instrumentationtests/src/org/webrtc/Camera2CapturerTest.java

@@ -237,6 +237,12 @@ public class Camera2CapturerTest {
     fixtures.switchCamera();
   }
 
+  @Test
+  @MediumTest
+  public void testSwitchVideoCapturerToSpecificCameraName() throws InterruptedException {
+    fixtures.switchCamera(true /* specifyCameraName */);
+  }
+
   @Test
   @MediumTest
   public void testCameraEvents() throws InterruptedException {

sdk/android/instrumentationtests/src/org/webrtc/CameraVideoCapturerTestFixtures.java

@@ -472,6 +472,10 @@ class CameraVideoCapturerTestFixtures {
   }
 
   public void switchCamera() throws InterruptedException {
+    switchCamera(false /* specifyCameraName */);
+  }
+
+  public void switchCamera(boolean specifyCameraName) throws InterruptedException {
     if (!testObjectFactory.haveTwoCameras()) {
       Logging.w(
           TAG, "Skipping test switch video capturer because the device doesn't have two cameras.");
@@ -487,18 +491,25 @@ class CameraVideoCapturerTestFixtures {
     // Array with one element to avoid final problem in nested classes.
     final boolean[] cameraSwitchSuccessful = new boolean[1];
     final CountDownLatch barrier = new CountDownLatch(1);
-    capturerInstance.capturer.switchCamera(new CameraVideoCapturer.CameraSwitchHandler() {
-      @Override
-      public void onCameraSwitchDone(boolean isFrontCamera) {
-        cameraSwitchSuccessful[0] = true;
-        barrier.countDown();
-      }
-      @Override
-      public void onCameraSwitchError(String errorDescription) {
-        cameraSwitchSuccessful[0] = false;
-        barrier.countDown();
-      }
-    });
+    final CameraVideoCapturer.CameraSwitchHandler cameraSwitchHandler =
+        new CameraVideoCapturer.CameraSwitchHandler() {
+          @Override
+          public void onCameraSwitchDone(boolean isFrontCamera) {
+            cameraSwitchSuccessful[0] = true;
+            barrier.countDown();
+          }
+          @Override
+          public void onCameraSwitchError(String errorDescription) {
+            cameraSwitchSuccessful[0] = false;
+            barrier.countDown();
+          }
+        };
+    if (specifyCameraName) {
+      String expectedCameraName = testObjectFactory.cameraEnumerator.getDeviceNames()[1];
+      capturerInstance.capturer.switchCamera(cameraSwitchHandler, expectedCameraName);
+    } else {
+      capturerInstance.capturer.switchCamera(cameraSwitchHandler);
+    }
     // Wait until the camera has been switched.
     barrier.await();