Since I am looking at this part of the code, I am working on this after speaking to adamk@ :)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f2e7ed013dcfe605fa9fb1918a54710429fc5448

commit f2e7ed013dcfe605fa9fb1918a54710429fc5448
Author: Mythri Alle <mythria@chromium.org>
Date: Tue Feb 20 12:32:54 2018

Remove the option to request a parser cache.

The parser cache in V8 is no longer used. Hence removing
the option to produce a parser cache.

Bug:  chromium:779254 
Change-Id: I70b0e211e63f312c701f4df3d57b3d75094cd762
Reviewed-on: https://chromium-review.googlesource.com/906988
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537761}
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/chrome/browser/about_flags.cc
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/content/common/content_switches_internal.cc
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/content/public/common/web_preferences.cc
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/content/public/common/web_preferences.h
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/third_party/WebKit/Source/bindings/core/v8/ScriptStreamer.cpp
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/third_party/WebKit/Source/bindings/core/v8/V8CacheOptions.h
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/third_party/WebKit/Source/bindings/core/v8/V8ScriptRunner.cpp
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/third_party/WebKit/Source/bindings/core/v8/V8ScriptRunnerTest.cpp
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp
[modify] https://crrev.com/f2e7ed013dcfe605fa9fb1918a54710429fc5448/third_party/WebKit/public/web/WebSettings.h

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/5a68df2ab528ae8248806ae4fe7f8b52a14f731c

commit 5a68df2ab528ae8248806ae4fe7f8b52a14f731c
Author: Mythri <mythria@chromium.org>
Date: Wed Feb 21 09:51:31 2018

Remove support for unused compile options.

We don't use parser caches anymore and request code caches
explicitly using ScriptCompiler::CreateCodeCache. Hence
removing the support for both parser cache and code cache options.
They are still retained in CompileOptions for backwards
compatibility. Apart from the api.cc, no other part should see
this option.

Bug:  chromium:779254 , chromium:783124
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ic8ad9afe3fa44bbb5adc71bdde59c0b4057a523d
Reviewed-on: https://chromium-review.googlesource.com/916261
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51416}
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/api.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/compiler.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/d8.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/background-parsing-task.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/background-parsing-task.h
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/parse-info.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/parse-info.h
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/parser.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/parser.h
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/parsing.cc
[delete] https://crrev.com/dea41745eec891609e691c9f2e7c9cc05fc8b9dc/src/parsing/preparse-data-format.h
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/preparse-data.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/preparse-data.h
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/parsing/preparser.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/snapshot/code-serializer.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/src/snapshot/code-serializer.h
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/test/cctest/cctest.h
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/test/cctest/test-api.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/test/cctest/test-debug.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/test/cctest/test-parsing.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/test/cctest/test-serialize.cc
[modify] https://crrev.com/5a68df2ab528ae8248806ae4fe7f8b52a14f731c/tools/parser-shell.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a0438e4abd34336060cd8bca46a0a2d36ed79d1a

commit a0438e4abd34336060cd8bca46a0a2d36ed79d1a
Author: Mythri Alle <mythria@chromium.org>
Date: Wed Jan 02 16:01:08 2019

Cleanup after removing deprecated v8 compile options

v8::ScriptCompiler::CompileOptions had several options which were
deprecated. The default case was added to be able to remove these
options from V8. With those options removed, we don't need the
default case.

Bug:  chromium:779254 , v8:8252 
Change-Id: Ifbbbf2a199e7897e64acfee353e85f8f0368ffb2
Reviewed-on: https://chromium-review.googlesource.com/c/1393263
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619410}
[modify] https://crrev.com/a0438e4abd34336060cd8bca46a0a2d36ed79d1a/third_party/blink/renderer/bindings/core/v8/v8_script_runner.cc
[modify] https://crrev.com/a0438e4abd34336060cd8bca46a0a2d36ed79d1a/third_party/blink/renderer/core/inspector/inspector_trace_events.cc