Move talk/app/webrtc to webrtc/api

The previously disabled warnings that were inherited from
talk/build/common.gypi are now replaced by target-specific disabling
of only the failing warnings. Additional disabling was needed since the stricter
compilation warnings that applies to code in webrtc/.

License headers will be updated in a follow-up CL.

Other modifications:
* Updated the header guards.
* Sorted the includes using chromium/src/tools/sort-headers.py
  except for these files:
  talk/app/webrtc/peerconnectionendtoend_unittest.cc
  talk/app/webrtc/java/jni/androidmediadecoder_jni.cc
  talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
  webrtc/media/devices/win32devicemanager.cc

The HAVE_SCTP define was added for the peerconnection_unittests target
in api_tests.gyp.

I also checked that none of
SRTP_RELATIVE_PATH
HAVE_SRTP
HAVE_WEBRTC_VIDEO
HAVE_WEBRTC_VOICE
were used by the talk/app/webrtc code.

For Chromium, the following changes will need to be applied to the roll CL that updates the
DEPS for WebRTC and libjingle:
https://codereview.chromium.org/1615433002

BUG=webrtc:5418
NOPRESUBMIT=True
R=deadbeef@webrtc.org, pthatcher@webrtc.org, tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1610243002 .

Cr-Commit-Position: refs/heads/master@{#11545}
diff --git a/webrtc/api/java/jni/classreferenceholder.cc b/webrtc/api/java/jni/classreferenceholder.cc
new file mode 100644
index 0000000..0625cc2
--- /dev/null
+++ b/webrtc/api/java/jni/classreferenceholder.cc
@@ -0,0 +1,152 @@
+/*
+ * libjingle
+ * Copyright 2015 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#include "webrtc/api/java/jni/classreferenceholder.h"
+
+#include "webrtc/api/java/jni/jni_helpers.h"
+
+namespace webrtc_jni {
+
+// ClassReferenceHolder holds global reference to Java classes in app/webrtc.
+class ClassReferenceHolder {
+ public:
+  explicit ClassReferenceHolder(JNIEnv* jni);
+  ~ClassReferenceHolder();
+
+  void FreeReferences(JNIEnv* jni);
+  jclass GetClass(const std::string& name);
+
+ private:
+  void LoadClass(JNIEnv* jni, const std::string& name);
+
+  std::map<std::string, jclass> classes_;
+};
+
+// Allocated in LoadGlobalClassReferenceHolder(),
+// freed in FreeGlobalClassReferenceHolder().
+static ClassReferenceHolder* g_class_reference_holder = nullptr;
+
+void LoadGlobalClassReferenceHolder() {
+  RTC_CHECK(g_class_reference_holder == nullptr);
+  g_class_reference_holder = new ClassReferenceHolder(GetEnv());
+}
+
+void FreeGlobalClassReferenceHolder() {
+  g_class_reference_holder->FreeReferences(AttachCurrentThreadIfNeeded());
+  delete g_class_reference_holder;
+  g_class_reference_holder = nullptr;
+}
+
+ClassReferenceHolder::ClassReferenceHolder(JNIEnv* jni) {
+  LoadClass(jni, "android/graphics/SurfaceTexture");
+  LoadClass(jni, "java/nio/ByteBuffer");
+  LoadClass(jni, "java/util/ArrayList");
+  LoadClass(jni, "org/webrtc/AudioTrack");
+  LoadClass(jni, "org/webrtc/CameraEnumerator");
+  LoadClass(jni, "org/webrtc/Camera2Enumerator");
+  LoadClass(jni, "org/webrtc/CameraEnumerationAndroid");
+  LoadClass(jni, "org/webrtc/DataChannel");
+  LoadClass(jni, "org/webrtc/DataChannel$Buffer");
+  LoadClass(jni, "org/webrtc/DataChannel$Init");
+  LoadClass(jni, "org/webrtc/DataChannel$State");
+  LoadClass(jni, "org/webrtc/EglBase");
+  LoadClass(jni, "org/webrtc/EglBase$Context");
+  LoadClass(jni, "org/webrtc/EglBase14$Context");
+  LoadClass(jni, "org/webrtc/IceCandidate");
+  LoadClass(jni, "org/webrtc/MediaCodecVideoEncoder");
+  LoadClass(jni, "org/webrtc/MediaCodecVideoEncoder$OutputBufferInfo");
+  LoadClass(jni, "org/webrtc/MediaCodecVideoEncoder$VideoCodecType");
+  LoadClass(jni, "org/webrtc/MediaCodecVideoDecoder");
+  LoadClass(jni, "org/webrtc/MediaCodecVideoDecoder$DecodedTextureBuffer");
+  LoadClass(jni, "org/webrtc/MediaCodecVideoDecoder$DecodedOutputBuffer");
+  LoadClass(jni, "org/webrtc/MediaCodecVideoDecoder$VideoCodecType");
+  LoadClass(jni, "org/webrtc/MediaSource$State");
+  LoadClass(jni, "org/webrtc/MediaStream");
+  LoadClass(jni, "org/webrtc/MediaStreamTrack$State");
+  LoadClass(jni, "org/webrtc/NetworkMonitor");
+  LoadClass(jni, "org/webrtc/NetworkMonitorAutoDetect$ConnectionType");
+  LoadClass(jni, "org/webrtc/NetworkMonitorAutoDetect$IPAddress");
+  LoadClass(jni, "org/webrtc/NetworkMonitorAutoDetect$NetworkInformation");
+  LoadClass(jni, "org/webrtc/PeerConnectionFactory");
+  LoadClass(jni, "org/webrtc/PeerConnection$BundlePolicy");
+  LoadClass(jni, "org/webrtc/PeerConnection$ContinualGatheringPolicy");
+  LoadClass(jni, "org/webrtc/PeerConnection$RtcpMuxPolicy");
+  LoadClass(jni, "org/webrtc/PeerConnection$IceConnectionState");
+  LoadClass(jni, "org/webrtc/PeerConnection$IceGatheringState");
+  LoadClass(jni, "org/webrtc/PeerConnection$IceTransportsType");
+  LoadClass(jni, "org/webrtc/PeerConnection$TcpCandidatePolicy");
+  LoadClass(jni, "org/webrtc/PeerConnection$KeyType");
+  LoadClass(jni, "org/webrtc/PeerConnection$SignalingState");
+  LoadClass(jni, "org/webrtc/RtpReceiver");
+  LoadClass(jni, "org/webrtc/RtpSender");
+  LoadClass(jni, "org/webrtc/SessionDescription");
+  LoadClass(jni, "org/webrtc/SessionDescription$Type");
+  LoadClass(jni, "org/webrtc/StatsReport");
+  LoadClass(jni, "org/webrtc/StatsReport$Value");
+  LoadClass(jni, "org/webrtc/SurfaceTextureHelper");
+  LoadClass(jni, "org/webrtc/VideoCapturerAndroid");
+  LoadClass(jni, "org/webrtc/VideoCapturerAndroid$NativeObserver");
+  LoadClass(jni, "org/webrtc/VideoRenderer$I420Frame");
+  LoadClass(jni, "org/webrtc/VideoTrack");
+}
+
+ClassReferenceHolder::~ClassReferenceHolder() {
+  RTC_CHECK(classes_.empty()) << "Must call FreeReferences() before dtor!";
+}
+
+void ClassReferenceHolder::FreeReferences(JNIEnv* jni) {
+  for (std::map<std::string, jclass>::const_iterator it = classes_.begin();
+      it != classes_.end(); ++it) {
+    jni->DeleteGlobalRef(it->second);
+  }
+  classes_.clear();
+}
+
+jclass ClassReferenceHolder::GetClass(const std::string& name) {
+  std::map<std::string, jclass>::iterator it = classes_.find(name);
+  RTC_CHECK(it != classes_.end()) << "Unexpected GetClass() call for: " << name;
+  return it->second;
+}
+
+void ClassReferenceHolder::LoadClass(JNIEnv* jni, const std::string& name) {
+  jclass localRef = jni->FindClass(name.c_str());
+  CHECK_EXCEPTION(jni) << "error during FindClass: " << name;
+  RTC_CHECK(localRef) << name;
+  jclass globalRef = reinterpret_cast<jclass>(jni->NewGlobalRef(localRef));
+  CHECK_EXCEPTION(jni) << "error during NewGlobalRef: " << name;
+  RTC_CHECK(globalRef) << name;
+  bool inserted = classes_.insert(std::make_pair(name, globalRef)).second;
+  RTC_CHECK(inserted) << "Duplicate class name: " << name;
+}
+
+// Returns a global reference guaranteed to be valid for the lifetime of the
+// process.
+jclass FindClass(JNIEnv* jni, const char* name) {
+  return g_class_reference_holder->GetClass(name);
+}
+
+}  // namespace webrtc_jni