Upstream Chrome on iOS source code [2/11].

ios/chrome/browser/ui/actions/README.md

Index: ios/chrome/browser/ui/actions/README.md
diff --git a/ios/chrome/browser/ui/actions/README.md b/ios/chrome/browser/ui/actions/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..21994e1d72059adc21e0f1fc3fc48f490203e225
--- /dev/null
+++ b/ios/chrome/browser/ui/actions/README.md
@@ -0,0 +1,26 @@
+# Actions.
+
+-----
+**The files in this directory are only used in the new iOS Chrome
+architecture.**
+-----
+
+This directory contains header files that define action protocols. Functionally
+these protocols are used to add application-specific methods to `UIResponder`,
+to allow controls to send action messages up the responder chain.
+
+These protocols headers are in this directory because, although they relate to
+specific UI features (settings, toolbar, etc), they will be used by different
+UI components, and should be independent of any specific UI implementation.
+
+Classes that instantiate controls that *send* the methods in one of these
+protocols will need to import the header for that protocol, but won't need to
+conform to it.
+
+Classes in the responder chain that *handle* any of these methods need to
+conform to the protocol.
+
+These protocols are specifically for use in the UI-layer target/action context,
+and shouldn't be used for other purposes. The `sender` parameter of any of these
+methods should always be an actual `UIControl` instance that the user is
+interacting with.