Delay loading Xsurface

We were loading xsurface at startup when FeedV2 was enabled.
Now it's only loaded when the feed surface is created.
This change shouldn't even affect normal startup when the NTP is
loading, because the startup() function is typically called after
creation of the feed surface in that case.

Bug: 1130677
Change-Id: If5edaa35fc387e92530b01e2421e1eef4b6ced82
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2422690Reviewed-by: Cathy Li <chili@chromium.org>
Commit-Queue: Dan H <harringtond@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811416}

chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedStreamSurface.java

@@ -152,7 +152,6 @@ public class FeedStreamSurface implements SurfaceActionsHandler, FeedActionsHand
         if (sStartupCalled) return;
         sStartupCalled = true;
         FeedServiceBridge.startup();
-        xSurfaceProcessScope();
         if (sSurfaces != null) {
             for (FeedStreamSurface surface : sSurfaces) {
                 surface.updateSurfaceOpenState();
@@ -933,6 +932,7 @@ public class FeedStreamSurface implements SurfaceActionsHandler, FeedActionsHand
         assert (mStreamContentVisible);
         // No feed content should exist.
         assert (mContentManager.getItemCount() == mHeaderCount);
+
         mOpened = true;
         FeedStreamSurfaceJni.get().surfaceOpened(mNativeFeedStreamSurface, FeedStreamSurface.this);
         mHybridListRenderer.onSurfaceOpened();