refactor: replace USE_X11 with OS_LINUX for sharing code with Ozone #25522

[khazifire]

Description of Change

This pull-request is a small first step in trying to bring support for Wayland to Electron. I'm planning to follow up on this with more pull-requests in an effort to upstream these Wayland patches.

However, those patches will need some adjustments in order to make them compatible with the upcoming Chromium changes (chromium#1085700) which will soon be merged into Electron (#25488). In particular, it should be taken into consideration that the USE_X11 and USE_OZONE build flags are no longer mutually exclusive.

Also, USE_X11 is going away so it might be desirable as a long term goal to remove it from Electron too and replace it with the Ozone equivalents.

With that in mind, this pull-request replaces a few instances of #if defined(USE_X11) with #if defined(OS_LINUX) where it was identified that the guarded code could be shared with Ozone.

The more meaningful changes will come in the upcoming pull-requests but I'll be waiting for these chromium changes to be pulled into Electron first (#24984, #25488).

Checklist

• PR description included and stakeholders cc'd (@zcbenz @hedgepigdaniel)
• npm test passes
• PR title follows semantic commit guidelines

Release Notes

Notes: none

[MonnetalX]

🔍 PR Link Analysis

🔗 Ranked Links

#1 these Wayland patches

🔍 The Wayland patches replace USE_X11 with OS_LINUX to allow sharing code between X11 and Ozone builds, enabling non-X11 Linux display servers like Wayland to reuse the same code paths.

#2 going away

🔍 The issue highlights that Electron's current reliance on X11 libraries makes it incompatible with Wayland, which is the default display server on modern Ubuntu and offers better performance on embedded devices.

#3 commit guidelines

🔍 The pull request aims to replace the USE_X11 preprocessor macro with OS_LINUX to allow sharing code between X11 and Wayland builds, as part of a broader effort to upstream Wayland support for Electron.

#4 https://github.com/electron/electron/blob/master/CONTRIBUTING.md

🔍 The CONTRIBUTING.md outlines the project's contribution guidelines, including the release cadence and support policy for Electron.

#5 chromium#1085700

🔍 The USE_X11 macro is being replaced with OS_LINUX to allow code sharing between X11 and Wayland (Ozone) builds, as both run on Linux.

#6 these chromium changes

🔍 The webpage describes Gerrit's code review workflow, which is relevant to the PR's goal of upstreaming Wayland patches through a structured review process.

[Copilot]

Pull request overview

This pull request claims to refactor preprocessor guards from USE_X11 to OS_LINUX to enable sharing code with Ozone/Wayland-related work, but the included diff only adds a placeholder text file.

Changes:

• Adds a new text.txt file containing a single temp line.

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[Copilot]

This change adds a new text.txt containing only temp, which appears unrelated to the PR goal of replacing USE_X11 with OS_LINUX. If this was an accidental/placeholder file, please remove it from the PR; if it’s intentional, clarify its purpose and name it accordingly.