tools/luci-go: remove old way of mapping isolate

It's now only mapped via CIPD, which is the right solution going forward.

Bug: 851596,865541
Change-Id: I25ddd0e059c818fafbc5587b06ff35b6c733a16e
Reviewed-on: https://chromium-review.googlesource.com/1143448
Commit-Queue: Marc-Antoine Ruel <maruel@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576550}

DEPS

@@ -1704,44 +1704,6 @@ hooks = [
                 '-d', 'src/chrome/build',
     ],
   },
-  # Pull luci-go binaries (isolate, swarming) using checked-in hashes.
-  # TODO(maruel): Remove, https://crbug.com/851596
-  {
-    'name': 'luci-go_win',
-    'pattern': '.',
-    'condition': 'host_os == "win"',
-    'action': [ 'python',
-                'src/third_party/depot_tools/download_from_google_storage.py',
-                '--no_resume',
-                '--no_auth',
-                '--bucket', 'chromium-luci',
-                '-d', 'src/tools/luci-go/win64',
-    ],
-  },
-  {
-    'name': 'luci-go_mac',
-    'pattern': '.',
-    'condition': 'host_os == "mac"',
-    'action': [ 'python',
-                'src/third_party/depot_tools/download_from_google_storage.py',
-                '--no_resume',
-                '--no_auth',
-                '--bucket', 'chromium-luci',
-                '-d', 'src/tools/luci-go/mac64',
-    ],
-  },
-  {
-    'name': 'luci-go_linux',
-    'pattern': '.',
-    'condition': 'host_os == "linux"',
-    'action': [ 'python',
-                'src/third_party/depot_tools/download_from_google_storage.py',
-                '--no_resume',
-                '--no_auth',
-                '--bucket', 'chromium-luci',
-                '-d', 'src/tools/luci-go/linux64',
-    ],
-  },
   # Pull the Syzygy binaries, used for optimization and instrumentation.
   # Remove this as soon as the zap_timestamp.exe utility is no longer used.
   # See https://crbug.com/821764#c3.

tools/luci-go/.gitignore

@@ -1,6 +1,3 @@
 /isolate
 /isolate.exe
-/linux64/isolate
-/mac64/isolate
-/win64/isolate.exe
 .versions