Revert of [tracing] Dump child processes' memory metrics in browser

base/trace_event/process_memory_totals_dump_provider_unittest.cc

+// Copyright 2015 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.
+
+#include "base/trace_event/process_memory_totals_dump_provider.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "base/trace_event/process_memory_dump.h"
+#include "base/trace_event/process_memory_totals.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace trace_event {
+
+TEST(ProcessMemoryTotalsDumpProviderTest, DumpRSS) {
+  const MemoryDumpArgs high_detail_args = {MemoryDumpLevelOfDetail::DETAILED};
+  auto pmtdp = ProcessMemoryTotalsDumpProvider::GetInstance();
+  scoped_ptr<ProcessMemoryDump> pmd_before(new ProcessMemoryDump(nullptr));
+  scoped_ptr<ProcessMemoryDump> pmd_after(new ProcessMemoryDump(nullptr));
+
+  ProcessMemoryTotalsDumpProvider::rss_bytes_for_testing = 1024;
+  pmtdp->OnMemoryDump(high_detail_args, pmd_before.get());
+
+  // Pretend that the RSS of the process increased of +1M.
+  const size_t kAllocSize = 1048576;
+  ProcessMemoryTotalsDumpProvider::rss_bytes_for_testing += kAllocSize;
+
+  pmtdp->OnMemoryDump(high_detail_args, pmd_after.get());
+
+  ProcessMemoryTotalsDumpProvider::rss_bytes_for_testing = 0;
+
+  ASSERT_TRUE(pmd_before->has_process_totals());
+  ASSERT_TRUE(pmd_after->has_process_totals());
+
+  const uint64_t rss_before =
+      pmd_before->process_totals()->resident_set_bytes();
+  const uint64_t rss_after = pmd_after->process_totals()->resident_set_bytes();
+
+  EXPECT_NE(0U, rss_before);
+  EXPECT_NE(0U, rss_after);
+
+  EXPECT_EQ(rss_after - rss_before, kAllocSize);
+}
+
+}  // namespace trace_event
+}  // namespace base