Add support for creating HW codecs in VideoProcessor tests.

webrtc/modules/video_coding/codecs/test/android_test_initializer.cc

+/*
+ *  Copyright 2017 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 <pthread.h>

[brandtr, 2017/02/13 12:40:26]

This file is inspired by
https://cs.chromium.org/chromium/src/third_party/webrtc/pc/test/androidtestin...
and
https://cs.chromium.org/chromium/src/third_party/webrtc/modules/audio_device/....

The point of this code is to dynamically load the Java classes from
webrtc/sdk/android/src/jni, so that we can instantiate Android HW codecs in the
C++ code. Since we don't control the JNI_OnLoad method (that one is defined in
the NativeTest harness of //testing/android), we explicitly load our Java
classes using appropriate calls to the functions in this file.

+
+#include "webrtc/base/ignore_wundef.h"
+#include "webrtc/modules/video_coding/codecs/test/android_test_initializer.h"
+#include "webrtc/sdk/android/src/jni/classreferenceholder.h"
+#include "webrtc/sdk/android/src/jni/jni_helpers.h"
+
+// Note: this dependency is dangerous since it reaches into Chromium's base.
+// There's a risk of e.g. macro clashes. This file may only be used in tests.
+// Since we use Chrome's build system for creating the gtest binary, this should
+// be fine.
+RTC_PUSH_IGNORING_WUNDEF()
+#include "base/android/jni_android.h"
+RTC_POP_IGNORING_WUNDEF()
+
+#include "webrtc/base/checks.h"
+
+namespace webrtc {
+
+namespace {
+
+static pthread_once_t g_initialize_once = PTHREAD_ONCE_INIT;
+static pthread_once_t g_free_once = PTHREAD_ONCE_INIT;
+
+// There can only be one JNI_OnLoad in each binary. So since this is a GTEST
+// C++ runner binary, we want to initialize the same global objects we normally
+// do if this had been a Java binary.
+void EnsureInitializedOnce() {
+  RTC_CHECK(::base::android::IsVMInitialized());
+  JNIEnv* jni = ::base::android::AttachCurrentThread();
+  JavaVM* jvm = NULL;
+  RTC_CHECK_EQ(0, jni->GetJavaVM(&jvm));
+
+  jint ret = webrtc_jni::InitGlobalJniVariables(jvm);
+  RTC_DCHECK_GE(ret, 0);
+
+  webrtc_jni::LoadGlobalClassReferenceHolder();
+}
+
+void EnsureFreedOnce() {
+  webrtc_jni::FreeGlobalClassReferenceHolder();
+}
+
+}  // namespace
+
+void InitializeAndroidObjects() {
+  RTC_CHECK_EQ(0, pthread_once(&g_initialize_once, &EnsureInitializedOnce));
+}
+
+void FreeAndroidObjects() {
+  RTC_CHECK_EQ(0, pthread_once(&g_free_once, &EnsureFreedOnce));
+}
+
+}  // namespace webrtc