docs: add note about win_delay_load_hook (#15766)

docs/api/breaking-changes.md

@@ -57,6 +57,14 @@ app.getGPUInfo('complete')
 app.getGPUInfo('basic')
 ```
 
+## `win_delay_load_hook`
+
+When building native modules for windows, the `win_delay_load_hook` variable in
+the module's `binding.gyp` must be true (which is the default). If this hook is
+not present, then the native module will fail to load on Windows, with an error
+message like `Cannot find module`. See the [native module
+guide](/docs/tutorial/using-native-node-modules.md) for more.
+
 
 # Breaking API Changes (3.0)
 

docs/tutorial/using-native-node-modules.md

@@ -83,9 +83,22 @@ If you installed a native module and found it was not working, you need to check
 following things:
 
 * The architecture of the module has to match Electron's architecture (ia32 or x64).
+* `win_delay_load_hook` is not set to `false` in the module's `binding.gyp`.
 * After you upgrade Electron, you usually need to rebuild the modules.
 * When in doubt, run `electron-rebuild` first.
 
+### A note about `win_delay_load_hook`
+
+On Windows, by default, node-gyp links native modules against `node.dll`.
+However, in Electron 4.x and higher, the symbols needed by native modules are
+exported by `electron.exe`, and there is no `node.dll` in Electron 4.x. In
+order to load native modules on Windows, node-gyp installs a [delay-load
+hook](https://msdn.microsoft.com/en-us/library/z9h1h6ty.aspx) that triggers
+when the native module is loaded, and redirects the `node.dll` reference to use
+the loading executable instead of looking for `node.dll` in the library search
+path (which would turn up nothing). As such, on Electron 4.x and higher,
+`'win_delay_load_hook': 'true'` is required to load native modules.
+
 ## Modules that rely on `prebuild`
 
 [`prebuild`](https://github.com/mafintosh/prebuild) provides a way to