Reshuffle include/ directory layout

This CL reorganizes the include/ directory as follows:
1. The immediate subdirectories of include/ are now the stable API
   surface exposed to all embedders, with the exception of ext/.
2. ext/ contains the unstable API surface that is exposed only to chrome.

Test: builds on all configurations and passes tests
Bug: 132678367
Change-Id: If638d4b4c150fd591cd1db851283b25ff6083ed6
diff --git a/src/tracing/core/tracing_service_impl_unittest.cc b/src/tracing/core/tracing_service_impl_unittest.cc
index 29e0dd2..c96d097 100644
--- a/src/tracing/core/tracing_service_impl_unittest.cc
+++ b/src/tracing/core/tracing_service_impl_unittest.cc
@@ -20,16 +20,16 @@
 
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
-#include "perfetto/base/file_utils.h"
-#include "perfetto/base/temp_file.h"
-#include "perfetto/base/utils.h"
-#include "perfetto/tracing/core/consumer.h"
-#include "perfetto/tracing/core/data_source_config.h"
-#include "perfetto/tracing/core/data_source_descriptor.h"
-#include "perfetto/tracing/core/producer.h"
-#include "perfetto/tracing/core/shared_memory.h"
-#include "perfetto/tracing/core/trace_packet.h"
-#include "perfetto/tracing/core/trace_writer.h"
+#include "perfetto/ext/base/file_utils.h"
+#include "perfetto/ext/base/temp_file.h"
+#include "perfetto/ext/base/utils.h"
+#include "perfetto/ext/tracing/core/consumer.h"
+#include "perfetto/ext/tracing/core/data_source_config.h"
+#include "perfetto/ext/tracing/core/data_source_descriptor.h"
+#include "perfetto/ext/tracing/core/producer.h"
+#include "perfetto/ext/tracing/core/shared_memory.h"
+#include "perfetto/ext/tracing/core/trace_packet.h"
+#include "perfetto/ext/tracing/core/trace_writer.h"
 #include "src/base/test/test_task_runner.h"
 #include "src/tracing/core/shared_memory_arbiter_impl.h"
 #include "src/tracing/core/trace_writer_impl.h"