Move camera implementation details away from the public API.

Moves CameraCapturer, CameraSession, Camera1Session and Camera2Session
away from the public API.

BUG=webrtc:7172

Review-Url: https://codereview.webrtc.org/2699713004
Cr-Commit-Position: refs/heads/master@{#16723}

webrtc/sdk/android/BUILD.gn

@@ -131,14 +131,10 @@ android_library("libjingle_peerconnection_java") {
     "api/org/webrtc/CallSessionFileRotatingLogSink.java",
     "api/org/webrtc/Camera1Capturer.java",
     "api/org/webrtc/Camera1Enumerator.java",
-    "api/org/webrtc/Camera1Session.java",
     "api/org/webrtc/Camera2Capturer.java",
     "api/org/webrtc/Camera2Enumerator.java",
-    "api/org/webrtc/Camera2Session.java",
-    "api/org/webrtc/CameraCapturer.java",
     "api/org/webrtc/CameraEnumerationAndroid.java",
     "api/org/webrtc/CameraEnumerator.java",
-    "api/org/webrtc/CameraSession.java",
     "api/org/webrtc/CameraVideoCapturer.java",
     "api/org/webrtc/DataChannel.java",
     "api/org/webrtc/DtmfSender.java",
@@ -181,6 +177,10 @@ android_library("libjingle_peerconnection_java") {
     "api/org/webrtc/VideoSource.java",
     "api/org/webrtc/VideoTrack.java",
     "api/org/webrtc/YuvConverter.java",
+    "src/java/org/webrtc/Camera1Session.java",
+    "src/java/org/webrtc/Camera2Session.java",
+    "src/java/org/webrtc/CameraCapturer.java",
+    "src/java/org/webrtc/CameraSession.java",
   ]
 
   deps = [

webrtc/sdk/android/src/java/org/webrtc/Camera1Session.java

@@ -22,7 +22,7 @@ import java.util.concurrent.TimeUnit;
 import org.webrtc.CameraEnumerationAndroid.CaptureFormat;
 
 @SuppressWarnings("deprecation")
-public class Camera1Session implements CameraSession {
+class Camera1Session implements CameraSession {
   private static final String TAG = "Camera1Session";
   private static final int NUMBER_OF_CAPTURE_BUFFERS = 3;
 

webrtc/sdk/android/src/java/org/webrtc/Camera2Session.java

@@ -31,7 +31,7 @@ import java.util.concurrent.TimeUnit;
 import org.webrtc.CameraEnumerationAndroid.CaptureFormat;
 
 @TargetApi(21)
-public class Camera2Session implements CameraSession {
+class Camera2Session implements CameraSession {
   private static final String TAG = "Camera2Session";
 
   private static final Histogram camera2StartTimeMsHistogram =

webrtc/sdk/android/src/java/org/webrtc/CameraCapturer.java

@@ -16,7 +16,7 @@ import android.os.Looper;
 import java.util.Arrays;
 
 @SuppressWarnings("deprecation")
-public abstract class CameraCapturer implements CameraVideoCapturer {
+abstract class CameraCapturer implements CameraVideoCapturer {
   enum SwitchState {
     IDLE, // No switch requested.
     PENDING, // Waiting for previous capture session to open.

webrtc/sdk/android/src/java/org/webrtc/CameraSession.java

@@ -10,7 +10,7 @@
 
 package org.webrtc;
 
-public interface CameraSession {
+interface CameraSession {
   enum FailureType { ERROR, DISCONNECTED }
 
   // Callbacks are fired on the camera thread.