Reland "Move webrtc/{base => rtc_base}" (https://codereview.webrtc.org/2877023002)

Reland the base->rtc_base without adding stub headers (will be
done in follow-up CL). This preserves git blame history of all files.

BUG=webrtc:7634
NOTRY=True
TBR=kwiberg@webrtc.org

Change-Id: Iea3bb6f3f67b8374c96337b63e8f5aa3e6181012
Reviewed-on: https://chromium-review.googlesource.com/554611
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18821}

webrtc/rtc_base/bufferqueue.cc

@@ -0,0 +1,94 @@
+/*
+ *  Copyright 2015 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 "webrtc/base/bufferqueue.h"
+
+#include <algorithm>
+
+namespace rtc {
+
+BufferQueue::BufferQueue(size_t capacity, size_t default_size)
+    : capacity_(capacity), default_size_(default_size) {
+}
+
+BufferQueue::~BufferQueue() {
+  CritScope cs(&crit_);
+
+  for (Buffer* buffer : queue_) {
+    delete buffer;
+  }
+  for (Buffer* buffer : free_list_) {
+    delete buffer;
+  }
+}
+
+size_t BufferQueue::size() const {
+  CritScope cs(&crit_);
+  return queue_.size();
+}
+
+void BufferQueue::Clear() {
+  CritScope cs(&crit_);
+  while (!queue_.empty()) {
+    free_list_.push_back(queue_.front());
+    queue_.pop_front();
+  }
+}
+
+bool BufferQueue::ReadFront(void* buffer, size_t bytes, size_t* bytes_read) {
+  CritScope cs(&crit_);
+  if (queue_.empty()) {
+    return false;
+  }
+
+  bool was_writable = queue_.size() < capacity_;
+  Buffer* packet = queue_.front();
+  queue_.pop_front();
+
+  bytes = std::min(bytes, packet->size());
+  memcpy(buffer, packet->data(), bytes);
+  if (bytes_read) {
+    *bytes_read = bytes;
+  }
+  free_list_.push_back(packet);
+  if (!was_writable) {
+    NotifyWritableForTest();
+  }
+  return true;
+}
+
+bool BufferQueue::WriteBack(const void* buffer, size_t bytes,
+                            size_t* bytes_written) {
+  CritScope cs(&crit_);
+  if (queue_.size() == capacity_) {
+    return false;
+  }
+
+  bool was_readable = !queue_.empty();
+  Buffer* packet;
+  if (!free_list_.empty()) {
+    packet = free_list_.back();
+    free_list_.pop_back();
+  } else {
+    packet = new Buffer(bytes, default_size_);
+  }
+
+  packet->SetData(static_cast<const uint8_t*>(buffer), bytes);
+  if (bytes_written) {
+    *bytes_written = bytes;
+  }
+  queue_.push_back(packet);
+  if (!was_readable) {
+    NotifyReadableForTest();
+  }
+  return true;
+}
+
+}  // namespace rtc