[webkit-changes] [WebKit/WebKit] 7cfbb0: Remove JSC VM usage from LegacyCDMSessionClearKey

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 7cfbb042f9c0cca987611f667c6e0968756b1241
      https://github.com/WebKit/WebKit/commit/7cfbb042f9c0cca987611f667c6e0968756b1241
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2023-07-24 (Mon, 24 Jul 2023)

  Changed paths:
    M Source/WebCore/Modules/encryptedmedia/legacy/LegacyCDMSessionClearKey.cpp

  Log Message:
  -----------
  Remove JSC VM usage from LegacyCDMSessionClearKey
https://bugs.webkit.org/show_bug.cgi?id=259386
rdar://112642265

Reviewed by Darin Adler.

LegacyCDMSessionClearKey is creating JSC VM and JSGlobalObject just to parse JSON!!
This is significantly costly. JSC::VM and JSGlobalObject are large JS environments.
Instantiation takes some time & it takes memory. They should not be required just to parse JSON.
Furthermore, this code runs on GPUProcess, and this part is the sole reason why GPUProcess still
creates JSC VM.

We should just use WTF::JSON::Value.

* Source/WebCore/Modules/encryptedmedia/legacy/LegacyCDMSessionClearKey.cpp:
(WebCore::CDMSessionClearKey::update):
(WebCore::CDMSessionClearKey::cachedKeyForKeyID const):
(WebCore::clearKeyVM): Deleted.

Canonical link: https://commits.webkit.org/266282@main