[ja] Sync with 470a0c5b5017990a230bb417704513d046bee909

Documented:

 * `@large`
 * `@medium`
 * `@small`
 * `timeoutForLargeTests`
 * `timeoutForMediumTests`
 * `timeoutForSmallTests`
[ja] Sync with 02830444d6fcce507097d1f7683af3e9a1d4d1c6

Documented `@coversDefaultClass`.
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[ja] Update translation