Enable overlay scrollbars on ChromeOS

content/browser/site_per_process_browsertest.cc

Index: content/browser/site_per_process_browsertest.cc
diff --git a/content/browser/site_per_process_browsertest.cc b/content/browser/site_per_process_browsertest.cc
index 55a2ab9ccfdf381c510fc51fe2d1ba762dbe1398..f8170e0592ce6b9cd0c488c1b4672b1aa0ac2037 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -69,6 +69,7 @@
 #include "ui/events/event_utils.h"
 #include "ui/events/latency_info.h"
 #include "ui/gfx/geometry/point.h"
+#include "ui/native_theme/native_theme_switches.h"
 
 #if defined(USE_AURA)
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
@@ -552,6 +553,11 @@ std::string SitePerProcessBrowserTest::DepictFrameTree(FrameTreeNode* node) {
 void SitePerProcessBrowserTest::SetUpCommandLine(
     base::CommandLine* command_line) {
   IsolateAllSitesForTesting(command_line);
+#if !defined(OS_ANDROID)
+  // TODO(bokan): Needed for scrollability check in
+  // FrameOwnerPropertiesPropagationScrolling. crbug.com/662196.
+  command_line->AppendSwitch(switches::kDisableOverlayScrollbar);
+#endif
 };
 
 void SitePerProcessBrowserTest::SetUpOnMainThread() {
@@ -2966,6 +2972,8 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
 // Verify that "scrolling" property on frame elements propagates to child frames
 // correctly.
 // Does not work on android since android has scrollbars overlayed.
+// TODO(bokan): Pretty soon most/all platforms will use overlay scrollbars. This
+// test should find a better way to check for scrollability. crbug.com/662196.
 #if defined(OS_ANDROID)
 #define MAYBE_FrameOwnerPropertiesPropagationScrolling \
         DISABLED_FrameOwnerPropertiesPropagationScrolling