Allow testing browser controls with rootScroller

This patch is split off from https://crrev.com/c/516554/. It prepares
the testing infrastructure for follow up patches and should make it
cleaner to test browser control behavior from root scroller tests.

All rootScroller related tests have been moved into their own directory
and we add a new virtual test suite using the Android set of flags for
the rootScroller tests.

I've also added an internal method for controlling the state of
browser controls as far as Blink can tell. This will be used from
followup patches to test behavior with the browser controls in various
states.

Bug: 505516
Change-Id: Iaed2d03c0e8aae4800644649bc4d8e7fce691cdc
Reviewed-on: https://chromium-review.googlesource.com/548975
Commit-Queue: David Bokan <[email protected]>
Reviewed-by: Philip Rogers <[email protected]>
Cr-Commit-Position: refs/heads/master@{#484745}
diff --git a/third_party/WebKit/LayoutTests/VirtualTestSuites b/third_party/WebKit/LayoutTests/VirtualTestSuites
index d0da258..afd07d72 100644
--- a/third_party/WebKit/LayoutTests/VirtualTestSuites
+++ b/third_party/WebKit/LayoutTests/VirtualTestSuites
@@ -188,6 +188,16 @@
              "--disable-composited-antialiasing"]
   },
   {
+    "prefix": "android",
+    "base": "fast/rootscroller",
+    "args": ["--enable-features=OverlayScrollbar", "--enable-threaded-compositing",
+             "--enable-fixed-position-compositing", "--enable-prefer-compositing-to-lcd-text",
+             "--enable-composited-scrolling-for-frames", "--enable-gesture-tap-highlight", "--enable-pinch",
+             "--force-overlay-fullscreen-video", "--enable-overscroll-notifications",
+             "--enable-fixed-layout", "--enable-viewport", "--disable-canvas-aa",
+             "--disable-composited-antialiasing"]
+  },
+  {
     "prefix": "media-gpu-accelerated",
     "base": "http/tests/media/media-source",
     "args": ["--use-gpu-in-tests"]
@@ -239,6 +249,11 @@
   },
   {
     "prefix": "rootlayerscrolls",
+    "base": "fast/rootscroller",
+    "args": ["--root-layer-scrolls"]
+  },
+  {
+    "prefix": "rootlayerscrolls",
     "base": "fast/history/scroll-restoration",
     "args": ["--root-layer-scrolls"]
   },