[Reland #1] macOS: Fix a bug in logic to get all memory regions.

components/tracing/common/process_metrics_memory_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 "components/tracing/common/process_metrics_memory_dump_provider.h"
 
 #include <stdint.h>
 
 #include <memory>
 #include <unordered_set>
@@ skipping 392 matching lines @@
     }
 
     if (region.mapped_file.find("AppKit") != std::string::npos) {
       found_appkit = true;
     }
   }
   EXPECT_GT(components_unittests_resident_pages, 0u);
   EXPECT_TRUE(found_appkit);
 }
 
-TEST(ProcessMetricsMemoryDumpProviderTest, NoDuplicateRegions) {
-  using VMRegion = base::trace_event::ProcessMemoryMaps::VMRegion;
-  ProcessMetricsMemoryDumpProvider mdp(base::kNullProcessId);
-  base::trace_event::MemoryDumpArgs args;
-  base::trace_event::ProcessMemoryDump dump(nullptr, args);
-  ASSERT_TRUE(mdp.DumpProcessMemoryMaps(args, &dump));
-  ASSERT_TRUE(dump.has_process_mmaps());
-
-  std::vector<VMRegion> regions;
-  regions.reserve(dump.process_mmaps()->vm_regions().size());
-  for (const VMRegion& region : dump.process_mmaps()->vm_regions())
-    regions.push_back(region);
-  std::sort(regions.begin(), regions.end(),
-            [](const VMRegion& a, const VMRegion& b) -> bool {
-              return a.start_address < b.start_address;
-            });
-  uint64_t last_address = 0;
-  for (const VMRegion& region : regions) {
-    EXPECT_GE(region.start_address, last_address);
-    last_address = region.start_address + region.size_in_bytes;
-  }
-}
-
 #endif  // defined(OS_MACOSX)
 }  // namespace tracing