Merging latest changes from the Feed repo up to 5c177df.

This merge includes the following commits:

commit 5c177dff913851f5adaf4c536c67154c4c1041a7
Author:     Dan Anderson <danrand@google.com>
AuthorDate: Tue Jul 28 12:29:32 2020 -0700
Commit:     Copybara-Service <copybara-worker@google.com>
CommitDate: Tue Jul 28 12:30:21 2020 -0700

    Adds ActionSurface to feed_action.proto

    PiperOrigin-RevId: 323628979
    Change-Id: Ia0e187327c6720e225b2c54f35ca23df73c08d2d

Change-Id: I22e19a8cb9a2dbf7fb6ec2c08aab706cc643bdb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2343555
Auto-Submit: Carlos Knippschild <carlosk@chromium.org>
Reviewed-by: Dan H <harringtond@chromium.org>
Commit-Queue: Dan H <harringtond@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796198}

chrome/android/feed/merging.md

@@ -8,4 +8,4 @@ Commits that don't touch these files do not cause changes here.
 The hash below represents the last commit from that repo that was reviewed for
 the potential need to merge here.
 
-Last checked commit ID: 8fb7fd9a80f7512cb78178b83f017d82d04f9b14
+Last checked commit ID: 5c177dff913851f5adaf4c536c67154c4c1041a7

components/feed/core/proto/wire/feed_action.proto

@@ -50,6 +50,15 @@ message FeedAction {
       CLIENT_CACHE = 2;
     }
 
+    // The surface an action was taken on.
+    enum ActionSurface {
+      UNKNOWN_SURFACE = 0;
+      ANDROID_CHROME_NEW_TAB = 7;
+    }
+
+    // What surface the action came from - AGA, iGA, -1, secondary screen etc.
+    optional ActionSurface action_surface = 5;
+
     // Where the action came from on the client.
     // Optional: This field is purely for diagnostics.
     optional ActionOrigin action_origin = 4;