[tracing] Implement composable memory usage estimators.

base/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 881 matching lines @@
     "timer/hi_res_timer_manager_win.cc",
     "timer/mock_timer.cc",
     "timer/mock_timer.h",
     "timer/timer.cc",
     "timer/timer.h",
     "trace_event/auto_open_close_event.cc",
     "trace_event/auto_open_close_event.h",
     "trace_event/blame_context.cc",
     "trace_event/blame_context.h",
     "trace_event/common/trace_event_common.h",
+    "trace_event/estimate_memory_usage.h",

[Primiano Tucci (use gerrit), 2016/11/08 14:09:16]

Generally all the source file names I see are nouns.
Maybe memory_usage_estimator.h?

     "trace_event/heap_profiler.h",
     "trace_event/heap_profiler_allocation_context.cc",
     "trace_event/heap_profiler_allocation_context.h",
     "trace_event/heap_profiler_allocation_context_tracker.cc",
     "trace_event/heap_profiler_allocation_context_tracker.h",
     "trace_event/heap_profiler_allocation_register.cc",
     "trace_event/heap_profiler_allocation_register.h",
     "trace_event/heap_profiler_allocation_register_posix.cc",
     "trace_event/heap_profiler_allocation_register_win.cc",
     "trace_event/heap_profiler_heap_dump_writer.cc",
@@ skipping 1054 matching lines @@
     "threading/worker_pool_posix_unittest.cc",
     "threading/worker_pool_unittest.cc",
     "time/pr_time_unittest.cc",
     "time/time_unittest.cc",
     "time/time_win_unittest.cc",
     "timer/hi_res_timer_manager_unittest.cc",
     "timer/mock_timer_unittest.cc",
     "timer/timer_unittest.cc",
     "tools_sanity_unittest.cc",
     "trace_event/blame_context_unittest.cc",
+    "trace_event/estimate_memory_usage_unittest.cc",
     "trace_event/heap_profiler_allocation_context_tracker_unittest.cc",
     "trace_event/heap_profiler_allocation_register_unittest.cc",
     "trace_event/heap_profiler_heap_dump_writer_unittest.cc",
     "trace_event/heap_profiler_stack_frame_deduplicator_unittest.cc",
     "trace_event/heap_profiler_type_name_deduplicator_unittest.cc",
     "trace_event/java_heap_dump_provider_android_unittest.cc",
     "trace_event/memory_allocator_dump_unittest.cc",
     "trace_event/memory_dump_manager_unittest.cc",
     "trace_event/process_memory_dump_unittest.cc",
     "trace_event/trace_config_unittest.cc",
@@ skipping 481 matching lines @@
 }
 
 fuzzer_test("base_json_correctness_fuzzer") {
   sources = [
     "json/correctness_fuzzer.cc",
   ]
   deps = [
     ":base",
   ]
 }