PPB_HostResolver

PPAPI Method Assumes Threads Emscripten Web API Limitations
Create x GAP GAP (partial) - No direct equivalent
Resolve x GAP GAP (partial) - No direct equivalent
GetCanonicalName x GAP GAP (partial) - No direct equivalent
GetNetAddressCount x GAP GAP (partial) - No direct equivalent
GetNetAddress x GAP GAP (partial) - No direct equivalent

PPB_NetAddress

PPAPI Method Assumes Threads Emscripten Web API Limitations
CreateFromIPv4Address x GAP GAP (partial) - No direct equivalent
CreateFromIPv6Address x GAP GAP (partial) - No direct equivalent
GetFamily x GAP GAP (partial) - No direct equivalent
DescribeAsString x GAP GAP (partial) - No direct equivalent
DescribeAsIPv4Address x GAP GAP (partial) - No direct equivalent
DescribeAsIPv6Address x GAP GAP (partial) - No direct equivalent

PPB_NetworkList

PPAPI Method Assumes Threads Emscripten Web API Limitations
GetCount x GAP GAP - No direct equivalent
GetName x GAP GAP - No direct equivalent
GetType x GAP GAP - No direct equivalent
GetState x GAP GAP - No direct equivalent
GetIpAddress x GAP GAP - No direct equivalent
GetDisplayName x GAP GAP - No direct equivalent
GetMTU x GAP GAP - No direct equivalent

PPB_NetworkMonitor

PPAPI Method Assumes Threads Emscripten Web API Limitations
Create x GAP GAP - No direct equivalent
UpdateNetworkList x GAP GAP - No direct equivalent

PPB_NetworkProxy

PPAPI Method Assumes Threads Emscripten Web API Limitations
GetProxyForURL x GAP GAP - No direct equivalent

PPB_TCPSocket and PPB_UDPSocket

There is not a direct 1:1 mapping for migration. Instead, we have outlined some user scenarios below and what the recommended migration path is.
Use Case Recommendations
Screen sharing getDisplayMedia and WebRTC ( demo)
Loading from a local server to minimize bandwidth usage XHR, Fetch, Streams, Service Worker, Cache APIs
Loading from a local instance of a web app / Connecting to a local instance of a web app WebRTC
Chat WebSocket*
Realtime audio/video communication WebRTC
Collaboration WebSocket*
Realtime multiplayer games WebTransport** unless P2P in which case WebRTC (or WebTransport over RTCIceTransport)
Realtime interactive streaming WebTransport**
Communicating with legacy server Proxy server or middleware to do protocol conversion. Feedback to bit.ly/network-api-gaps
*: Or WebTransport in the future
**: See chromestatus for availability