Breakdown nonprofiled memory regions (f.k.a. 'unknown'), and add new policy files.

tools/deep_memory_profiler/policy.l1.txt

+heap profile policy: POLICY_DEEP_2
+# Read policy.README for description of this file.
+second                          optional        optional
+mmap-profiler                   mmap    .*(ProfilerMalloc|MemoryRegionMap::).*
+mmap-tcmalloc                   mmap    .*(DoAllocWithArena|SbrkSysAllocator::Alloc|MmapSysAllocator::Alloc|LowLevelAlloc::Alloc|LowLevelAlloc::AllocWithArena).*
+FROM_HERE_FOR_TOTAL             optional        optional
+mustbezero                      optional        optional
+nonprofiled-absent              optional        optional
+nonprofiled-anonymous           optional        optional
+nonprofiled-file-exec           optional        optional
+nonprofiled-file-nonexec        optional        optional
+nonprofiled-stack               optional        optional
+nonprofiled-other               optional        optional
+no-bucket                       default default
+mmap-v8-heap-newspace           mmap    .*v8::internal::NewSpace::SetUp.*
+mmap-v8-heap-coderange          mmap    .*v8::internal::CodeRange::SetUp.*
+mmap-v8-heap-pagedspace         mmap    .*v8::internal::PagedSpace::AllocateRaw.*
+mmap-v8-other                   mmap    .*v8::.*
+mmap-catch-all                  mmap    .*
+tc-v8                           malloc  .*v8::.*
+tc-skia                         malloc  .*Sk[A-Za-z_]+::.*
+tc-webkit-catch-all             malloc  .*(WTF::|WebCore::|WebKit::).*
+tc-unknown-string               malloc  .*std::basic_string::_Rep::_S_create.*
+tc-catch-all                    malloc  .*
+tc-unused                       default default
+UNTIL_HERE_FOR_TOTAL            optional        optional
+total-exclude-profiler          optional        optional
+total                           optional        optional
+anonymous                       optional        optional
+file-exec                       optional        optional
+file-nonexec                    optional        optional
+stack                           optional        optional
+other                           optional        optional
+mmap-total-log                  default default
+mmap-no-log                     default default
+mmap-total-record               default default
+other-total-log                 default default
+tc-total-log                    default default
+tc-no-log                       default default
+tc-total-record                 default default
+tc-total                        default default