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/src/jni/logging/logsink.cc

@@ -0,0 +1,35 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "sdk/android/src/jni/logging/logsink.h"
+
+#include "sdk/android/generated_logging_jni/jni/JNILogging_jni.h"
+
+namespace webrtc {
+namespace jni {
+
+JNILogSink::JNILogSink(JNIEnv* env, const JavaRef<jobject>& j_logging)
+    : j_logging_(env, j_logging) {}
+JNILogSink::~JNILogSink() = default;
+
+void JNILogSink::OnLogMessage(const std::string& msg,
+                              rtc::LoggingSeverity severity,
+                              const char* tag) {
+  JNIEnv* env = AttachCurrentThreadIfNeeded();
+  Java_JNILogging_logToInjectable(env, j_logging_, NativeToJavaString(env, msg),
+                                  NativeToJavaInteger(env, severity),
+                                  NativeToJavaString(env, tag));
+}
+
+void JNILogSink::OnLogMessage(const std::string& msg) {
+  RTC_NOTREACHED();
+}
+
+}  // namespace jni
+}  // namespace webrtc

sdk/android/src/jni/logging/logsink.h

@@ -0,0 +1,39 @@
+/*
+ *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef SDK_ANDROID_SRC_JNI_LOGGING_LOGSINK_H_
+#define SDK_ANDROID_SRC_JNI_LOGGING_LOGSINK_H_
+
+#include <string>
+
+#include "rtc_base/logging.h"
+#include "sdk/android/native_api/jni/java_types.h"
+#include "sdk/android/src/jni/jni_helpers.h"
+
+namespace webrtc {
+namespace jni {
+
+class JNILogSink : public rtc::LogSink {
+ public:
+  JNILogSink(JNIEnv* env, const JavaRef<jobject>& j_logging);
+  ~JNILogSink() override;
+
+  void OnLogMessage(const std::string& msg,
+                    rtc::LoggingSeverity severity,
+                    const char* tag) override;
+  void OnLogMessage(const std::string& msg) override;
+
+ private:
+  const ScopedJavaGlobalRef<jobject> j_logging_;
+};
+
+}  // namespace jni
+}  // namespace webrtc
+
+#endif  // SDK_ANDROID_SRC_JNI_LOGGING_LOGSINK_H_

sdk/android/src/jni/pc/peerconnectionfactory.cc

@@ -27,6 +27,7 @@
 #include "sdk/android/generated_peerconnection_jni/jni/PeerConnectionFactory_jni.h"
 #include "sdk/android/native_api/jni/java_types.h"
 #include "sdk/android/src/jni/jni_helpers.h"
+#include "sdk/android/src/jni/logging/logsink.h"
 #include "sdk/android/src/jni/pc/androidnetworkmonitor.h"
 #include "sdk/android/src/jni/pc/audio.h"
 #include "sdk/android/src/jni/pc/icecandidate.h"
@@ -81,6 +82,9 @@ static char* field_trials_init_string = nullptr;
 static bool factory_static_initialized = false;
 static bool video_hw_acceleration_enabled = true;
 
+// Set in PeerConnectionFactory_InjectLoggable().
+static std::unique_ptr<JNILogSink> jni_log_sink;
+
 void PeerConnectionFactoryNetworkThreadReady() {
   RTC_LOG(LS_INFO) << "Network thread JavaCallback";
   JNIEnv* env = AttachCurrentThreadIfNeeded();
@@ -503,5 +507,29 @@ static jlong JNI_PeerConnectionFactory_GetNativePeerConnectionFactory(
   return jlongFromPointer(factoryFromJava(native_factory));
 }
 
+static void JNI_PeerConnectionFactory_InjectLoggable(
+    JNIEnv* jni,
+    const JavaParamRef<jclass>&,
+    const JavaParamRef<jobject>& j_logging,
+    jint nativeSeverity) {
+  // If there is already a LogSink, remove it from LogMessage.
+  if (jni_log_sink) {
+    rtc::LogMessage::RemoveLogToStream(jni_log_sink.get());
+  }
+  jni_log_sink = rtc::MakeUnique<JNILogSink>(jni, j_logging);
+  rtc::LogMessage::AddLogToStream(
+      jni_log_sink.get(), static_cast<rtc::LoggingSeverity>(nativeSeverity));
+  rtc::LogMessage::LogToDebug(rtc::LS_NONE);
+}
+
+static void JNI_PeerConnectionFactory_DeleteLoggable(
+    JNIEnv* jni,
+    const JavaParamRef<jclass>&) {
+  if (jni_log_sink) {
+    rtc::LogMessage::RemoveLogToStream(jni_log_sink.get());
+    jni_log_sink.reset();
+  }
+}
+
 }  // namespace jni
 }  // namespace webrtc