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/event_tracer_unittest.cc

@@ -0,0 +1,82 @@
+/*
+ *  Copyright (c) 2012 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/event_tracer.h"
+
+#include "webrtc/base/trace_event.h"
+#include "webrtc/system_wrappers/include/static_instance.h"
+#include "webrtc/test/gtest.h"
+
+namespace {
+
+class TestStatistics {
+ public:
+  TestStatistics() : events_logged_(0) {
+  }
+
+  void Reset() {
+    events_logged_ = 0;
+  }
+
+  void Increment() {
+    ++events_logged_;
+  }
+
+  int Count() const { return events_logged_; }
+
+  static TestStatistics* Get() {
+    static TestStatistics* test_stats = nullptr;
+    if (!test_stats)
+      test_stats = new TestStatistics();
+    return test_stats;
+  }
+
+ private:
+  int events_logged_;
+};
+
+static const unsigned char* GetCategoryEnabledHandler(const char* name) {
+  return reinterpret_cast<const unsigned char*>("test");
+}
+
+static void AddTraceEventHandler(char phase,
+                                 const unsigned char* category_enabled,
+                                 const char* name,
+                                 unsigned long long id,
+                                 int num_args,
+                                 const char** arg_names,
+                                 const unsigned char* arg_types,
+                                 const unsigned long long* arg_values,
+                                 unsigned char flags) {
+  TestStatistics::Get()->Increment();
+}
+
+}  // namespace
+
+namespace webrtc {
+
+TEST(EventTracerTest, EventTracerDisabled) {
+  {
+    TRACE_EVENT0("test", "EventTracerDisabled");
+  }
+  EXPECT_FALSE(TestStatistics::Get()->Count());
+  TestStatistics::Get()->Reset();
+}
+
+TEST(EventTracerTest, ScopedTraceEvent) {
+  SetupEventTracer(&GetCategoryEnabledHandler, &AddTraceEventHandler);
+  {
+    TRACE_EVENT0("test", "ScopedTraceEvent");
+  }
+  EXPECT_EQ(2, TestStatistics::Get()->Count());
+  TestStatistics::Get()->Reset();
+}
+
+}  // namespace webrtc