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/cryptstring.cc

@@ -0,0 +1,75 @@
+/*
+ *  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/cryptstring.h"
+
+namespace rtc {
+
+size_t EmptyCryptStringImpl::GetLength() const {
+  return 0;
+}
+
+void EmptyCryptStringImpl::CopyTo(char* dest, bool nullterminate) const {
+  if (nullterminate) {
+    *dest = '\0';
+  }
+}
+
+std::string EmptyCryptStringImpl::UrlEncode() const {
+  return "";
+}
+
+CryptStringImpl* EmptyCryptStringImpl::Copy() const {
+  return new EmptyCryptStringImpl();
+}
+
+void EmptyCryptStringImpl::CopyRawTo(std::vector<unsigned char>* dest) const {
+  dest->clear();
+}
+
+CryptString::CryptString() : impl_(new EmptyCryptStringImpl()) {
+}
+
+CryptString::CryptString(const CryptString& other)
+    : impl_(other.impl_->Copy()) {
+}
+
+CryptString::CryptString(const CryptStringImpl& impl) : impl_(impl.Copy()) {
+}
+
+CryptString::~CryptString() = default;
+
+size_t InsecureCryptStringImpl::GetLength() const {
+  return password_.size();
+}
+
+void InsecureCryptStringImpl::CopyTo(char* dest, bool nullterminate) const {
+  memcpy(dest, password_.data(), password_.size());
+  if (nullterminate)
+    dest[password_.size()] = 0;
+}
+
+std::string InsecureCryptStringImpl::UrlEncode() const {
+  return password_;
+}
+
+CryptStringImpl* InsecureCryptStringImpl::Copy() const {
+  InsecureCryptStringImpl* copy = new InsecureCryptStringImpl;
+  copy->password() = password_;
+  return copy;
+}
+
+void InsecureCryptStringImpl::CopyRawTo(
+    std::vector<unsigned char>* dest) const {
+  dest->resize(password_.size());
+  memcpy(&dest->front(), password_.data(), password_.size());
+}
+
+};  // namespace rtc