[DimitarCC]

This pull request improves the management of GPU memory and texture cache in relation to the web overlay (browser) layer. The main changes ensure that the system proactively frees up GPU resources as soon as the browser session starts, not just when the web layer becomes visible. This helps prevent memory exhaustion issues when the browser is loading, even before it's displayed.

Key changes include:

Web overlay session tracking and notification:

• Added m_session_open to track when the browser (producer) session is active, and a new sessionOpen() method to expose this state. The callback for freeing textures (m_on_show) is now triggered both when the session starts (frame file mapped) and when the layer becomes visible, ensuring GPU memory is freed in both cases. [1] [2] [3]
• Updated logic to reset m_session_open when the browser session ends, such as when the shared memory file is unmapped or the producer process is gone. [1] [2]

Texture cache management and logging:

• Changed the EGL device code to consider the web overlay session as "active" if either the layer was recently visible or the session is open, so texture budgets and cache releases are handled proactively.
• Updated debug log messages to clarify when textures are being released due to the web overlay being "active" (session open or visible), rather than just "visible." [1] [2]