linux: theme scrollbars from GTK theme

Pick the color of the slider's thumbpart and rail from the GTK theme. 
We cannot match the exact visual appearance of the GTK theme, as 
rendering engines can make arbitrary changes to the actual visual 
appearance. But by sampling a representative set of pixels, we ensure 
that we will at least match the general color scheme. 

BUG=10949
patch by <markus [at] chromium>
original review: http://codereview.chromium.org/400027/show

Review URL: http://codereview.chromium.org/466080

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34183 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 9 insertions, 0 deletions

diff --git a/chrome/common/renderer_preferences.h b/chrome/common/renderer_preferences.h
index b08548e..a982d57 100644
--- a/chrome/common/renderer_preferences.h
+++ b/chrome/common/renderer_preferences.h
@@ -51,6 +51,12 @@ struct RendererPreferences {
   // The color of the focus ring. Currently only used on Linux.
   SkColor focus_ring_color;
 
+  // The color of different parts of the scrollbar. Currently only used on
+  // Linux.
+  SkColor thumb_active_color;
+  SkColor thumb_inactive_color;
+  SkColor track_color;
+
   // Browser wants a look at all top level requests
   bool browser_handles_top_level_requests;
 
@@ -61,6 +67,9 @@ struct RendererPreferences {
         subpixel_rendering(
             RENDERER_PREFERENCES_SUBPIXEL_RENDERING_SYSTEM_DEFAULT),
         focus_ring_color(0),
+        thumb_active_color(0),
+        thumb_inactive_color(0),
+        track_color(0),
         browser_handles_top_level_requests(false) {
   }
 };