What's this for? 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1465e995b89191c56885c93c0ca43543e9d8cad4

commit 1465e995b89191c56885c93c0ca43543e9d8cad4
Author: sigbjornf <sigbjornf@opera.com>
Date: Tue Apr 19 12:24:40 2016

Update Blink GC plugin to reflect that Oilpan is now always enabled.

With the Blink codebase having migrated to an Oilpan only state, update
the GC plugin accordingly:

 - drop handling of RawPtr<T>, it no longer exists.
 - remove !ENABLE(OILPAN) specific checks.

R=haraken
BUG= 604463 

Review URL: https://codereview.chromium.org/1895943002

Cr-Commit-Position: refs/heads/master@{#388188}

[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/BlinkGCPluginOptions.h
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/CheckFieldsVisitor.cpp
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/CheckFieldsVisitor.h
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/Edge.h
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/RecordInfo.cpp
[add] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/tests/raw_ptr_to_gc_managed_class.flags
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/tests/raw_ptr_to_gc_managed_class.h
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/tests/raw_ptr_to_gc_managed_class.txt
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/tests/raw_ptr_to_gc_managed_class_error.h
[modify] https://crrev.com/1465e995b89191c56885c93c0ca43543e9d8cad4/tools/clang/blink_gc_plugin/tests/raw_ptr_to_gc_managed_class_error.txt

Re #2 - see https://www.chromium.org/blink/blink-gc for (many) details on what this issue touches on; hth.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/01d8280352825197825e139a60f38ab0cf11b9b8

commit 01d8280352825197825e139a60f38ab0cf11b9b8
Author: sigbjornf <sigbjornf@opera.com>
Date: Fri Apr 29 12:44:34 2016

blink_gc_plugin: drop no-op options.

With the updated GC clang plugin that rolled out as part of  issue 604993 ,
we can now assume that the enable-oilpan and warn-raw-ptr options are
by default always on & consequently doesn't need to be passed in by
blink_gc_plugin_flags.py

R=
BUG= 604463 , 604476 

Review-Url: https://codereview.chromium.org/1926003003
Cr-Commit-Position: refs/heads/master@{#390631}

[modify] https://crrev.com/01d8280352825197825e139a60f38ab0cf11b9b8/tools/clang/scripts/blink_gc_plugin_flags.py