4 Blink View Transition Pseudo-Element Tree and Layout Integration

The provided text explains how the Blink rendering engine manages View Transitions by generating a temporary pseudo-element subtree to represent page changes. This system acts as an overlay, capturing snapshots of old and new states and organizing them into a hierarchy of group, image-pair, and content pseudos. These elements are not part of the standard DOM, but are instead specialized layout boxes that the engine styles and paints to create smooth visual continuities. The documentation details how C++ base classes enforce tree rules, resolve custom styles, and maintain intrinsic sizes for snapshots during the transition. Ultimately, the process ensures that transitioning elements can be animated and blended seamlessly without disrupting the underlying document structure.