Refactor: Remove master/slave terminology from window.context API (Fi…

[itzperi]

…xes #30789)

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[Copilot]

Pull Request Overview

This pull request refactors the window.context API to eliminate problematic master/slave terminology, replacing it with primary/secondary terminology while maintaining full backward compatibility.

Key changes include:

• Function and property renames from master/slave to primary/secondary terminology
• Addition of legacy compatibility properties and methods
• Comprehensive test updates to use the new terminology

Reviewed Changes

Copilot reviewed 24 out of 24 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
test/unit/test-3p.js	Updates test cases to use computeInPrimaryFrame and primary/secondary terminology
test/unit/ads/test-ssp.js	Updates SSP ad tests to use new primary frame terminology
test/unit/ads/test-pubmine.js	Updates pubmine ad tests to use isPrimary property
test/unit/3p/test-ampcontext-integration.js	Updates integration tests to use primaryFrameSelection
test/integration/test-amp-ad-3p.js	Updates integration tests to expect new context properties
src/3p-frame.js	Updates comment to use primary frame terminology
extensions/amp-ad/0.1/test/test-amp-ad-xorigin-iframe-handler.js	Updates iframe handler tests to use primary terminology
extensions/amp-ad/0.1/amp-ad-xorigin-iframe-handler.js	Updates iframe handling logic to check for primary frames
build-system/externs/amp.extern.js	Adds new primary properties while preserving legacy ones
ads/vendors/*.js	Updates vendor implementations to use new primary frame API
WINDOW_CONTEXT_API_REFACTORING.md	Documentation of the refactoring effort
3p/ampcontext.js	Updates context implementation comments
3p/ampcontext-integration.js	Core implementation of new primary frame API with legacy compatibility
3p/3p.js	Implementation of computeInPrimaryFrame with legacy wrapper

[Copilot]

The indentation is inconsistent - this line appears to have extra spaces compared to the surrounding code structure.

Suggested change

	global.context.primary.Swoop.announcePlace(global, data);
	}
	global.context.primary.Swoop.announcePlace(global, data);
	}

[erwinmombay]

heya our expert in the ads space is currently on leave and I don't feel comfortable approving this without their review, so it might take a bit for to get to this review.