Enable the flag of direct manipulation on Mac and Linux

After we enable the direct manipulation on Windows, we want to enable
it on Mac and Linux as well.

Bug: 854354
Change-Id: I9115f8933588c68b75e15411f0ea3e502d229e24
Reviewed-on: https://chromium-review.googlesource.com/1106971
Commit-Queue: Lan Wei <[email protected]>
Reviewed-by: Jochen Eisinger <[email protected]>
Reviewed-by: Navid Zolghadr <[email protected]>
Cr-Commit-Position: refs/heads/master@{#569457}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 5cfb8071..c630f0c 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -3330,12 +3330,13 @@
      flag_descriptions::kClickToOpenPDFDescription, kOsAll,
      FEATURE_VALUE_TYPE(features::kClickToOpenPDFPlaceholder)},
 
-#if defined(OS_WIN)
+#if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
     {"direct-manipulation-stylus",
      flag_descriptions::kDirectManipulationStylusName,
-     flag_descriptions::kDirectManipulationStylusDescription, kOsWin,
+     flag_descriptions::kDirectManipulationStylusDescription,
+     kOsWin | kOsMac | kOsLinux,
      FEATURE_VALUE_TYPE(features::kDirectManipulationStylus)},
-#endif  // defined(OS_WIN)
+#endif  // defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
 
 #if !defined(OS_ANDROID)
     {"remove-deprecared-gaia-signin-endpoint",