Make scrollAnimatorEnabled work on Mac like it does on other platforms

content/browser/theme_helper_mac.mm

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/theme_helper_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/command_line.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/sdk_forward_declarations.h"
 #include "base/strings/sys_string_conversions.h"
+#include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/content_switches.h"
 
 using content::RenderProcessHost;
+using content::RenderProcessHostImpl;
 using content::ThemeHelperMac;
 
 namespace {
 
-bool GetScrollAnimationEnabled() {
-  bool enabled = false;
-  id value = nil;
-  if (base::mac::IsOSMountainLionOrLater()) {
-    value = [[NSUserDefaults standardUserDefaults]
-        objectForKey:@"NSScrollAnimationEnabled"];
-  } else {
-    value = [[NSUserDefaults standardUserDefaults]
-        objectForKey:@"AppleScrollAnimationEnabled"];
-  }
-  if (value)
-    enabled = [value boolValue];
-  return enabled;
-}
-
 blink::WebScrollbarButtonsPlacement GetButtonPlacement() {
   NSString* scrollbar_variant = [[NSUserDefaults standardUserDefaults]
       objectForKey:@"AppleScrollBarVariant"];
   if ([scrollbar_variant isEqualToString:@"Single"])
     return blink::WebScrollbarButtonsPlacementSingle;
   else if ([scrollbar_variant isEqualToString:@"DoubleMin"])
     return blink::WebScrollbarButtonsPlacementDoubleStart;
   else if ([scrollbar_variant isEqualToString:@"DoubleBoth"])
     return blink::WebScrollbarButtonsPlacementDoubleBoth;
   else
     return blink::WebScrollbarButtonsPlacementDoubleEnd;
 }
 
 void FillScrollbarThemeParams(ViewMsg_UpdateScrollbarTheme_Params* params) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
   [defaults synchronize];
 
   params->initial_button_delay =
       [defaults floatForKey:@"NSScrollerButtonDelay"];
   params->autoscroll_button_delay =
       [defaults floatForKey:@"NSScrollerButtonPeriod"];
   params->jump_on_track_click =
       [defaults boolForKey:@"AppleScrollerPagingBehavior"];
   params->preferred_scroller_style =
       ThemeHelperMac::GetPreferredScrollerStyle();
-  params->scroll_animation_enabled = GetScrollAnimationEnabled();
   params->button_placement = GetButtonPlacement();
 }
 
 ViewMsg_SystemColorsChanged* CreateSystemColorsChangedMessage() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
   [defaults synchronize];
 
   return new ViewMsg_SystemColorsChanged(
@@ skipping 92 matching lines @@
 }
 
 + (void)notifyPrefsChangedWithRedraw:(BOOL)redraw {
   ViewMsg_UpdateScrollbarTheme_Params params;
   FillScrollbarThemeParams(&params);
   params.redraw = redraw;
 
   for (RenderProcessHost::iterator it(RenderProcessHost::AllHostsIterator());
        !it.IsAtEnd();
        it.Advance()) {
-    it.GetCurrentValue()->Send(new ViewMsg_UpdateScrollbarTheme(params));
+    RenderProcessHostImpl* rphi =
+        static_cast<RenderProcessHostImpl*>(it.GetCurrentValue());

[bokan, 2016/02/02 19:45:39]

In particular, I'm not sure if this is kosher - will RPH always be a RPHI?

+    rphi->RecomputeAndUpdateWebKitPreferences();
+    rphi->Send(new ViewMsg_UpdateScrollbarTheme(params));
   }
 }
 
 @end
 
 namespace content {
 
 // static
 ThemeHelperMac* ThemeHelperMac::GetInstance() {
   return base::Singleton<ThemeHelperMac,
@@ skipping 21 matching lines @@
                              const NotificationSource& source,
                              const NotificationDetails& details) {
   DCHECK_EQ(NOTIFICATION_RENDERER_PROCESS_CREATED, type);
 
   // When a new RenderProcess is created, send it the initial preference
   // parameters.
   ViewMsg_UpdateScrollbarTheme_Params params;
   FillScrollbarThemeParams(&params);
   params.redraw = false;
 
-  RenderProcessHost* rph = Source<RenderProcessHost>(source).ptr();
-  rph->Send(new ViewMsg_UpdateScrollbarTheme(params));
-  rph->Send(CreateSystemColorsChangedMessage());
+  RenderProcessHostImpl* rphi =

[bokan, 2016/02/02 19:45:39]

Ditto here

+      Source<content::RenderProcessHostImpl>(source).ptr();
+  rphi->RecomputeAndUpdateWebKitPreferences();
+  rphi->Send(new ViewMsg_UpdateScrollbarTheme(params));
+  rphi->Send(CreateSystemColorsChangedMessage());
 }
 
 }  // namespace content