Remove tools/android/heap_profiler

It is a standalone .so library meant to be LD_PRELOAD-ed
using awkward tricks into the Android zygote to get heap dumps.
Never worked too well in Chrome as it intercepted only malloc
calls, without being able to hook allocations in PartitionAlloc
or Blink GC.
This is subsumed by the work of crbug.com/602701 which
integrates native heap profiling with chrome://tracing and
supports all the major chrome allocators.
For future heap profiling adventures use
//components/tracing/docs/heap_profiler.md

This CL also removes //third_party/bsdtrees that was introduced
as a dependency to libheap_profiler. Nothing else seems to
depend on it.

BUG=382489

Review-Url: https://codereview.chromium.org/2105873005
Cr-Commit-Position: refs/heads/master@{#403179}

BUILD.gn

@@ -377,7 +377,6 @@ group("both_gn_and_gyp") {
       "//tools/android:push_apps_to_background",
       "//tools/android/audio_focus_grabber:audio_focus_grabber_apk",
       "//tools/android/customtabs_benchmark:customtabs_benchmark_apk",
-      "//tools/android/heap_profiler:heap_profiler_unittests",
       "//tools/android/kerberos/SpnegoAuthenticator:spnego_authenticator_apk",
       "//tools/cygprofile:cygprofile_unittests",
       "//ui/android:ui_junit_tests",

build/all.gyp

@@ -827,7 +827,6 @@
             '../skia/skia_tests.gyp:skia_unittests_apk',
             '../sql/sql.gyp:sql_unittests_apk',
             '../sync/sync.gyp:sync_unit_tests_apk',
-            '../tools/android/heap_profiler/heap_profiler.gyp:heap_profiler_unittests_apk',
             '../ui/android/ui_android.gyp:ui_android_unittests_apk',
             '../ui/android/ui_android.gyp:ui_junit_tests',
             '../ui/base/ui_base_tests.gyp:ui_base_unittests_apk',