Linux/CrOS smooth scrolling support - behind a flag.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 65e6a65d3482538ba159b3b936919d29a3c77699..73db98713bc108cab93ca1815cb040256d7b1403 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -145,6 +145,9 @@
       # Has no effect if 'clang' is not set as well.
       'clang_use_chrome_plugins%': 0,
 
+      # Smooth scrolling is disabled by default.
+      'enable_smooth_scrolling%': 0,

[tony, 2011/06/22 19:11:31]

You don't need to define this here.  It can just be pulled out one level.

+
       'conditions': [
         # Use Skia as WebKit renderer on Mac
         ['OS=="mac"', {
@@ -250,6 +253,7 @@
     'configuration_policy%': '<(configuration_policy)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'enable_register_protocol_handler%': '<(enable_register_protocol_handler)',
+    'enable_smooth_scrolling%': '<(enable_smooth_scrolling)',

[tony, 2011/06/22 19:11:31]

ie., at this level, just put:
# Smooth scrolling is disabled by default.
'enable_smooth_scrolling%': 0,

The nesting is only necessary if you needed to use it in a condition.

 
     # The release channel that this build targets. This is used to restrict
     # channel-specific build options, like which installer packages to create.