Reland "Injectable logging"

Any injected loggable or NativeLogger would be deleted if PCFactory
was reinitialized without calling setInjectableLogger. Now native
logging is not implemented as a Loggable, so it will remain active
unless a Loggable is injected.

This is a reland of 59216ec4a4151b1ba5478c8f2b5c9f01f4683d7f

Original change's description:
> Injectable logging
>
> Allows passing a Loggable to PCFactory.initializationOptions, which
> is then injected to Logging.java and logging.h. Future log messages
> in both Java and native will then be passed to this Loggable.
>
> Bug: webrtc:9225
> Change-Id: I2ff693380639448301a78a93dc11d3a0106f0967
> Reviewed-on: https://webrtc-review.googlesource.com/73243
> Commit-Queue: Paulina Hensman <phensman@webrtc.org>
> Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
> Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#23241}

Bug: webrtc:9225
Change-Id: I2fe3fbc8c323814284bb62e43fe1870bdab581ee
TBR: kwiberg
Reviewed-on: https://webrtc-review.googlesource.com/77140
Commit-Queue: Paulina Hensman <phensman@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23310}

sdk/android/api/org/webrtc/PeerConnectionFactory.java

@@ -13,6 +13,7 @@ package org.webrtc;
 import android.content.Context;
 import java.util.List;
 import javax.annotation.Nullable;
+import org.webrtc.Logging.Severity;
 import org.webrtc.audio.AudioDeviceModule;
 import org.webrtc.audio.LegacyAudioDeviceModule;
 
@@ -41,15 +42,20 @@ public class PeerConnectionFactory {
     final boolean enableInternalTracer;
     final boolean enableVideoHwAcceleration;
     final NativeLibraryLoader nativeLibraryLoader;
+    @Nullable Loggable loggable;
+    @Nullable Severity loggableSeverity;
 
     private InitializationOptions(Context applicationContext, String fieldTrials,
         boolean enableInternalTracer, boolean enableVideoHwAcceleration,
-        NativeLibraryLoader nativeLibraryLoader) {
+        NativeLibraryLoader nativeLibraryLoader, @Nullable Loggable loggable,
+        @Nullable Severity loggableSeverity) {
       this.applicationContext = applicationContext;
       this.fieldTrials = fieldTrials;
       this.enableInternalTracer = enableInternalTracer;
       this.enableVideoHwAcceleration = enableVideoHwAcceleration;
       this.nativeLibraryLoader = nativeLibraryLoader;
+      this.loggable = loggable;
+      this.loggableSeverity = loggableSeverity;
     }
 
     public static Builder builder(Context applicationContext) {
@@ -62,6 +68,8 @@ public class PeerConnectionFactory {
       private boolean enableInternalTracer = false;
       private boolean enableVideoHwAcceleration = true;
       private NativeLibraryLoader nativeLibraryLoader = new NativeLibrary.DefaultLoader();
+      @Nullable private Loggable loggable = null;
+      @Nullable private Severity loggableSeverity = null;
 
       Builder(Context applicationContext) {
         this.applicationContext = applicationContext;
@@ -87,9 +95,16 @@ public class PeerConnectionFactory {
         return this;
       }
 
+      public Builder setInjectableLogger(Loggable loggable, Severity severity) {
+        this.loggable = loggable;
+        this.loggableSeverity = severity;
+        return this;
+      }
+
       public PeerConnectionFactory.InitializationOptions createInitializationOptions() {
         return new PeerConnectionFactory.InitializationOptions(applicationContext, fieldTrials,
-            enableInternalTracer, enableVideoHwAcceleration, nativeLibraryLoader);
+            enableInternalTracer, enableVideoHwAcceleration, nativeLibraryLoader, loggable,
+            loggableSeverity);
       }
     }
   }
@@ -199,6 +214,16 @@ public class PeerConnectionFactory {
     if (options.enableInternalTracer && !internalTracerInitialized) {
       initializeInternalTracer();
     }
+    if (options.loggable != null) {
+      Logging.injectLoggable(options.loggable, options.loggableSeverity);
+      nativeInjectLoggable(new JNILogging(options.loggable), options.loggableSeverity.ordinal());
+    } else {
+      Logging.d(TAG,
+          "PeerConnectionFactory was initialized without an injected Loggable. "
+              + "Any existing Loggable will be deleted.");
+      Logging.deleteInjectedLoggable();
+      nativeDeleteLoggable();
+    }
   }
 
   private void checkInitializeHasBeenCalled() {
@@ -474,4 +499,6 @@ public class PeerConnectionFactory {
   private static native void nativeInvokeThreadsCallbacks(long factory);
   private static native void nativeFreeFactory(long factory);
   private static native long nativeGetNativePeerConnectionFactory(long factory);
+  private static native void nativeInjectLoggable(JNILogging jniLogging, int severity);
+  private static native void nativeDeleteLoggable();
 }