Make the workspace cycler animation parameters editable via chrome://gesture

ash/wm/workspace/workspace_cycler.cc

Index: ash/wm/workspace/workspace_cycler.cc
diff --git a/ash/wm/workspace/workspace_cycler.cc b/ash/wm/workspace/workspace_cycler.cc
index 5015fff092d2751c68333ac005200dbf8a121e1f..d7e7d6b72947266f5b794ac2b7add5f595f65c8e 100644
--- a/ash/wm/workspace/workspace_cycler.cc
+++ b/ash/wm/workspace/workspace_cycler.cc
@@ -7,18 +7,18 @@
 #include <cmath>
 
 #include "ash/shell.h"
+#include "ash/wm/workspace/workspace_cycler_configuration.h"
 #include "ash/wm/workspace/workspace_manager.h"
 #include "ui/base/events/event.h"
 #include "ui/base/events/event_utils.h"
 
+typedef ash::WorkspaceCyclerConfiguration Config;
+
 namespace ash {
 namespace internal {
 
 namespace {
 
-// The required vertical distance to initiate workspace cycling.
-const float kDistanceToInitiateWorkspaceCycling = 10.0f;
-
 // Returns true if cycling is allowed.
 bool IsCyclingAllowed() {
   // Cycling is disabled if the screen is locked or a modal dialog is open.
@@ -133,7 +133,10 @@ void WorkspaceCycler::OnScrollEvent(ui::ScrollEvent* event) {
   }
 
   if (state_ == NOT_CYCLING_TRACKING_SCROLL) {
-    if (fabs(scroll_x_) > kDistanceToInitiateWorkspaceCycling) {
+    double distance_to_initiate_cycling = Config::GetDouble(
+        Config::DISTANCE_TO_INITIATE_CYCLING);
+
+    if (fabs(scroll_x_) > distance_to_initiate_cycling) {
       // Only initiate workspace cycling if there recently was a significant
       // amount of vertical movement as opposed to vertical movement
       // accumulated over a long horizontal three finger scroll.
@@ -141,7 +144,7 @@ void WorkspaceCycler::OnScrollEvent(ui::ScrollEvent* event) {
       scroll_y_ = 0.0f;
     }
 
-    if (fabs(scroll_y_) >= kDistanceToInitiateWorkspaceCycling)
+    if (fabs(scroll_y_) >= distance_to_initiate_cycling)
       SetState(STARTING_CYCLING);
   }