fling: Remove a bunch of code for configuring fling curves.

The fling curve for touchpad and touchscreen used to be configurable for
experimenting with, but these parameters have been stable for a long time now.
So make the values default, and remove all the code and preferences that were
necessary for the configurability.

BUG=none
R=avi@chromium.org, kenrb@chromium.org, sky@chromium.org, wjmaclean@chromium.org

Review URL: https://codereview.chromium.org/586933003

Cr-Commit-Position: refs/heads/master@{#296652}

24 files changed, 47 insertions, 432 deletions

diff --git a/chrome/browser/renderer_preferences_util.cc b/chrome/browser/renderer_preferences_util.cc
index 8cc171c..519e63b 100644
--- a/chrome/browser/renderer_preferences_util.cc
+++ b/chrome/browser/renderer_preferences_util.cc
@@ -38,7 +38,6 @@ void UpdateFromSystemSettings(
 
 #if defined(USE_DEFAULT_RENDER_THEME)
   prefs->focus_ring_color = SkColorSetRGB(0x4D, 0x90, 0xFE);
-
 #if defined(OS_CHROMEOS)
   // This color is 0x544d90fe modulated with 0xffffff.
   prefs->active_selection_bg_color = SkColorSetRGB(0xCB, 0xE4, 0xFA);
@@ -46,19 +45,6 @@ void UpdateFromSystemSettings(
   prefs->inactive_selection_bg_color = SkColorSetRGB(0xEA, 0xEA, 0xEA);
   prefs->inactive_selection_fg_color = SK_ColorBLACK;
 #endif
-
-  prefs->touchpad_fling_profile[0] =
-      pref_service->GetDouble(prefs::kFlingCurveTouchpadAlpha);
-  prefs->touchpad_fling_profile[1] =
-      pref_service->GetDouble(prefs::kFlingCurveTouchpadBeta);
-  prefs->touchpad_fling_profile[2] =
-      pref_service->GetDouble(prefs::kFlingCurveTouchpadGamma);
-  prefs->touchscreen_fling_profile[0] =
-      pref_service->GetDouble(prefs::kFlingCurveTouchscreenAlpha);
-  prefs->touchscreen_fling_profile[1] =
-      pref_service->GetDouble(prefs::kFlingCurveTouchscreenBeta);
-  prefs->touchscreen_fling_profile[2] =
-      pref_service->GetDouble(prefs::kFlingCurveTouchscreenGamma);
 #endif
 
 #if defined(TOOLKIT_VIEWS)
diff --git a/chrome/browser/resources/gesture_config.js b/chrome/browser/resources/gesture_config.js
index 2c077e8..099c288 100644
--- a/chrome/browser/resources/gesture_config.js
+++ b/chrome/browser/resources/gesture_config.js
@@ -179,30 +179,6 @@ function GestureConfig() {
       units: 'pixels'
     },
     {
-      key: 'fling_acceleration_curve_coefficient_0',
-      label: 'Touchscreen Fling Acceleration',
-      units: 'x<sup>3</sup>',
-      min: '-1'
-    },
-    {
-      key: 'fling_acceleration_curve_coefficient_1',
-      label: '+',
-      units: 'x<sup>2</sup>',
-      min: '-1'
-    },
-    {
-      key: 'fling_acceleration_curve_coefficient_2',
-      label: '+',
-      units: 'x<sup>1</sup>',
-      min: '-1'
-    },
-    {
-      key: 'fling_acceleration_curve_coefficient_3',
-      label: '+',
-      units: 'x<sup>0</sup>',
-      min: '-1'
-    },
-    {
       key: 'tab_scrub_activation_delay_in_ms',
       label: 'Tab scrub auto activation delay, (-1 for never)',
       units: 'milliseconds'
@@ -265,57 +241,6 @@ function OverscrollConfig() {
 }
 
 /**
- * Returns a GeneralConfig for configuring flingcurve.* preferences.
- * @return {object} A GeneralConfig object.
- */
-function FlingConfig() {
-  /** @const */ var FLING_TITLE = 'Fling Configuration';
-
-  /** @const */ var FLING_PREFIX = 'flingcurve.';
-
-  var FLING_FIELDS = [
-    {
-      key: 'touchscreen_alpha',
-      label: 'Touchscreen fling deacceleration coefficients',
-      units: 'alpha',
-      min: '-inf'
-    },
-    {
-      key: 'touchscreen_beta',
-      label: '',
-      units: 'beta',
-      min: '-inf'
-    },
-    {
-      key: 'touchscreen_gamma',
-      label: '',
-      units: 'gamma',
-      min: '-inf'
-    },
-    {
-      key: 'touchpad_alpha',
-      label: 'Touchpad fling deacceleration coefficients',
-      units: 'alpha',
-      min: '-inf'
-    },
-    {
-      key: 'touchpad_beta',
-      label: '',
-      units: 'beta',
-      min: '-inf'
-    },
-    {
-      key: 'touchpad_gamma',
-      label: '',
-      units: 'gamma',
-      min: '-inf'
-    },
-  ];
-
-  return new GeneralConfig(FLING_TITLE, FLING_PREFIX, FLING_FIELDS);
-}
-
-/**
  * WebUI instance for configuring preference values related to gesture input.
  */
 window.gesture_config = {
@@ -329,13 +254,9 @@ window.gesture_config = {
     var o = OverscrollConfig();
     o.buildAll();
 
-    var f = FlingConfig();
-    f.buildAll();
-
     $('reset-all-button').onclick = function() {
       g.onReset();
       o.onReset();
-      f.onReset();
     };
   },
 
diff --git a/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc b/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc
index 3163ef0..b529fea 100644
--- a/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc
+++ b/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc
@@ -91,10 +91,6 @@ class GesturePrefsObserver : public KeyedService {
 // Note that this collection of settings should correspond to the settings used
 // in ui/events/gestures/gesture_configuration.h
 const char* kPrefsToObserve[] = {
-  prefs::kFlingAccelerationCurveCoefficient0,
-  prefs::kFlingAccelerationCurveCoefficient1,
-  prefs::kFlingAccelerationCurveCoefficient2,
-  prefs::kFlingAccelerationCurveCoefficient3,
   prefs::kFlingMaxCancelToDownTimeInMs,
   prefs::kFlingMaxTapGapTimeInMs,
   prefs::kTabScrubActivationDelayInMS,
@@ -102,20 +98,26 @@ const char* kPrefsToObserve[] = {
   prefs::kSemiLongPressTimeInSeconds,
 };
 
-const char* kFlingTouchpadPrefs[] = {
-  prefs::kFlingCurveTouchpadAlpha,
-  prefs::kFlingCurveTouchpadBeta,
-  prefs::kFlingCurveTouchpadGamma
-};
-
-const char* kFlingTouchscreenPrefs[] = {
-  prefs::kFlingCurveTouchscreenAlpha,
-  prefs::kFlingCurveTouchscreenBeta,
-  prefs::kFlingCurveTouchscreenGamma,
+const char* kPrefsToRemove[] = {
+    "gesture.fling_acceleration_curve_coefficient_0",
+    "gesture.fling_acceleration_curve_coefficient_1",
+    "gesture.fling_acceleration_curve_coefficient_2",
+    "gesture.fling_acceleration_curve_coefficient_3",
+    "flingcurve.touchpad_alpha",
+    "flingcurve.touchpad_beta",
+    "flingcurve.touchpad_gamma",
+    "flingcurve.touchscreen_alpha",
+    "flingcurve.touchscreen_beta",
+    "flingcurve.touchscreen_gamma",
 };
 
 GesturePrefsObserver::GesturePrefsObserver(PrefService* prefs)
     : prefs_(prefs) {
+  for (size_t i = 0; i < arraysize(kPrefsToRemove); ++i) {
+    if (prefs->FindPreference(kPrefsToRemove[i]))
+      prefs->ClearPref(kPrefsToRemove[i]);
+  }
+
   registrar_.Init(prefs);
   registrar_.RemoveAll();
   base::Closure callback = base::Bind(&GesturePrefsObserver::Update,
@@ -131,11 +133,6 @@ GesturePrefsObserver::GesturePrefsObserver(PrefService* prefs)
   for (size_t i = 0; i < overscroll_prefs.size(); ++i)
     registrar_.Add(overscroll_prefs[i].pref_name, callback);
 
-  for (size_t i = 0; i < arraysize(kFlingTouchpadPrefs); ++i)
-    registrar_.Add(kFlingTouchpadPrefs[i], notify_callback);
-  for (size_t i = 0; i < arraysize(kFlingTouchscreenPrefs); ++i)
-    registrar_.Add(kFlingTouchscreenPrefs[i], notify_callback);
-
   Update();
 }
 
@@ -146,14 +143,6 @@ void GesturePrefsObserver::Shutdown() {
 }
 
 void GesturePrefsObserver::Update() {
-  GestureConfiguration::set_fling_acceleration_curve_coefficients(0,
-      prefs_->GetDouble(prefs::kFlingAccelerationCurveCoefficient0));
-  GestureConfiguration::set_fling_acceleration_curve_coefficients(1,
-      prefs_->GetDouble(prefs::kFlingAccelerationCurveCoefficient1));
-  GestureConfiguration::set_fling_acceleration_curve_coefficients(2,
-      prefs_->GetDouble(prefs::kFlingAccelerationCurveCoefficient2));
-  GestureConfiguration::set_fling_acceleration_curve_coefficients(3,
-      prefs_->GetDouble(prefs::kFlingAccelerationCurveCoefficient3));
   GestureConfiguration::set_fling_max_cancel_to_down_time_in_ms(
       prefs_->GetInteger(prefs::kFlingMaxCancelToDownTimeInMs));
   GestureConfiguration::set_fling_max_tap_gap_time_in_ms(
@@ -161,11 +150,9 @@ void GesturePrefsObserver::Update() {
   GestureConfiguration::set_tab_scrub_activation_delay_in_ms(
       prefs_->GetInteger(prefs::kTabScrubActivationDelayInMS));
   GestureConfiguration::set_semi_long_press_time_in_seconds(
-      prefs_->GetDouble(
-          prefs::kSemiLongPressTimeInSeconds));
+      prefs_->GetDouble(prefs::kSemiLongPressTimeInSeconds));
   GestureConfiguration::set_max_separation_for_gesture_touches_in_pixels(
-      prefs_->GetDouble(
-          prefs::kMaxSeparationForGestureTouchesInPixels));
+      prefs_->GetDouble(prefs::kMaxSeparationForGestureTouchesInPixels));
 
   UpdateOverscrollPrefs();
 }
@@ -219,41 +206,8 @@ void GesturePrefsObserverFactoryAura::RegisterOverscrollPrefs(
   }
 }
 
-void GesturePrefsObserverFactoryAura::RegisterFlingCurveParameters(
-    user_prefs::PrefRegistrySyncable* registry) {
-  content::RendererPreferences def_prefs;
-
-  for (size_t i = 0; i < arraysize(kFlingTouchpadPrefs); i++)
-    registry->RegisterDoublePref(
-        kFlingTouchpadPrefs[i],
-        def_prefs.touchpad_fling_profile[i],
-        user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-
-  for (size_t i = 0; i < arraysize(kFlingTouchscreenPrefs); i++)
-    registry->RegisterDoublePref(
-        kFlingTouchscreenPrefs[i],
-        def_prefs.touchscreen_fling_profile[i],
-        user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-}
-
 void GesturePrefsObserverFactoryAura::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
-  registry->RegisterDoublePref(
-      prefs::kFlingAccelerationCurveCoefficient0,
-      GestureConfiguration::fling_acceleration_curve_coefficients(0),
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-  registry->RegisterDoublePref(
-      prefs::kFlingAccelerationCurveCoefficient1,
-      GestureConfiguration::fling_acceleration_curve_coefficients(1),
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-  registry->RegisterDoublePref(
-      prefs::kFlingAccelerationCurveCoefficient2,
-      GestureConfiguration::fling_acceleration_curve_coefficients(2),
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-  registry->RegisterDoublePref(
-      prefs::kFlingAccelerationCurveCoefficient3,
-      GestureConfiguration::fling_acceleration_curve_coefficients(3),
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterIntegerPref(
       prefs::kFlingMaxCancelToDownTimeInMs,
       GestureConfiguration::fling_max_cancel_to_down_time_in_ms(),
@@ -275,7 +229,6 @@ void GesturePrefsObserverFactoryAura::RegisterProfilePrefs(
       GestureConfiguration::max_separation_for_gesture_touches_in_pixels(),
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   RegisterOverscrollPrefs(registry);
-  RegisterFlingCurveParameters(registry);
 }
 
 bool
diff --git a/chrome/browser/ui/gesture_prefs_observer_factory_aura.h b/chrome/browser/ui/gesture_prefs_observer_factory_aura.h
index 7e71250..8621066 100644
--- a/chrome/browser/ui/gesture_prefs_observer_factory_aura.h
+++ b/chrome/browser/ui/gesture_prefs_observer_factory_aura.h
@@ -25,7 +25,6 @@ class GesturePrefsObserverFactoryAura
   virtual ~GesturePrefsObserverFactoryAura();
 
   void RegisterOverscrollPrefs(user_prefs::PrefRegistrySyncable* registry);
-  void RegisterFlingCurveParameters(user_prefs::PrefRegistrySyncable* registry);
 
   // BrowserContextKeyedServiceFactory:
   virtual KeyedService* BuildServiceInstanceFor(
diff --git a/chrome/browser/ui/webui/chromeos/salsa_ui.cc b/chrome/browser/ui/webui/chromeos/salsa_ui.cc
index 34c66ac..9a2afea 100644
--- a/chrome/browser/ui/webui/chromeos/salsa_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/salsa_ui.cc
@@ -26,10 +26,6 @@ namespace {
 
 const char* kWhitelist[] = {
   prefs::kMaxSeparationForGestureTouchesInPixels,
-  prefs::kFlingAccelerationCurveCoefficient0,
-  prefs::kFlingAccelerationCurveCoefficient1,
-  prefs::kFlingAccelerationCurveCoefficient2,
-  prefs::kFlingAccelerationCurveCoefficient3,
   prefs::kTabScrubActivationDelayInMS,
   prefs::kOverscrollHorizontalThresholdComplete,
   prefs::kOverscrollVerticalThresholdComplete,
@@ -37,12 +33,6 @@ const char* kWhitelist[] = {
   prefs::kOverscrollVerticalThresholdStart,
   prefs::kOverscrollHorizontalResistThreshold,
   prefs::kOverscrollVerticalResistThreshold,
-  prefs::kFlingCurveTouchscreenAlpha,
-  prefs::kFlingCurveTouchscreenBeta,
-  prefs::kFlingCurveTouchscreenGamma,
-  prefs::kFlingCurveTouchpadAlpha,
-  prefs::kFlingCurveTouchpadBeta,
-  prefs::kFlingCurveTouchpadGamma,
 };
 
 void RevertPreferences(PrefService* prefs,
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 79da55d..b257b01 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -2201,20 +2201,6 @@ const char kSemiLongPressTimeInSeconds[] =
     "gesture.semi_long_press_time_in_seconds";
 const char kTabScrubActivationDelayInMS[] =
     "gesture.tab_scrub_activation_delay_in_ms";
-const char kFlingAccelerationCurveCoefficient0[] =
-    "gesture.fling_acceleration_curve_coefficient_0";
-const char kFlingAccelerationCurveCoefficient1[] =
-    "gesture.fling_acceleration_curve_coefficient_1";
-const char kFlingAccelerationCurveCoefficient2[] =
-    "gesture.fling_acceleration_curve_coefficient_2";
-const char kFlingAccelerationCurveCoefficient3[] =
-    "gesture.fling_acceleration_curve_coefficient_3";
-const char kFlingCurveTouchpadAlpha[] = "flingcurve.touchpad_alpha";
-const char kFlingCurveTouchpadBeta[] = "flingcurve.touchpad_beta";
-const char kFlingCurveTouchpadGamma[] = "flingcurve.touchpad_gamma";
-const char kFlingCurveTouchscreenAlpha[] = "flingcurve.touchscreen_alpha";
-const char kFlingCurveTouchscreenBeta[] = "flingcurve.touchscreen_beta";
-const char kFlingCurveTouchscreenGamma[] = "flingcurve.touchscreen_gamma";
 const char kFlingMaxCancelToDownTimeInMs[] =
     "gesture.fling_max_cancel_to_down_time_in_ms";
 const char kFlingMaxTapGapTimeInMs[] =
diff --git a/chrome/common/pref_names.h b/chrome/common/pref_names.h
index a474abf..74e47fc 100644
--- a/chrome/common/pref_names.h
+++ b/chrome/common/pref_names.h
@@ -760,16 +760,6 @@ extern const char kShowLogoutButtonInTray[];
 extern const char kMaxSeparationForGestureTouchesInPixels[];
 extern const char kSemiLongPressTimeInSeconds[];
 extern const char kTabScrubActivationDelayInMS[];
-extern const char kFlingAccelerationCurveCoefficient0[];
-extern const char kFlingAccelerationCurveCoefficient1[];
-extern const char kFlingAccelerationCurveCoefficient2[];
-extern const char kFlingAccelerationCurveCoefficient3[];
-extern const char kFlingCurveTouchpadAlpha[];
-extern const char kFlingCurveTouchpadBeta[];
-extern const char kFlingCurveTouchpadGamma[];
-extern const char kFlingCurveTouchscreenAlpha[];
-extern const char kFlingCurveTouchscreenBeta[];
-extern const char kFlingCurveTouchscreenGamma[];
 extern const char kFlingMaxCancelToDownTimeInMs[];
 extern const char kFlingMaxTapGapTimeInMs[];
 extern const char kOverscrollHorizontalThresholdComplete[];
diff --git a/content/child/blink_platform_impl.cc b/content/child/blink_platform_impl.cc
index 85a391c..ca2392c 100644
--- a/content/child/blink_platform_impl.cc
+++ b/content/child/blink_platform_impl.cc
@@ -32,7 +32,7 @@
 #include "content/app/strings/grit/content_strings.h"
 #include "content/child/child_thread.h"
 #include "content/child/content_child_helpers.h"
-#include "content/child/fling_curve_configuration.h"
+#include "content/child/touch_fling_gesture_curve.h"
 #include "content/child/web_discardable_memory_impl.h"
 #include "content/child/web_socket_stream_handle_impl.h"
 #include "content/child/web_url_loader_impl.h"
@@ -422,7 +422,6 @@ BlinkPlatformImpl::BlinkPlatformImpl()
       shared_timer_fire_time_(0.0),
       shared_timer_fire_time_was_set_while_suspended_(false),
       shared_timer_suspended_(0),
-      fling_curve_configuration_(new FlingCurveConfiguration),
       current_thread_slot_(&DestroyCurrentThread) {}
 
 BlinkPlatformImpl::~BlinkPlatformImpl() {
@@ -998,12 +997,7 @@ blink::WebGestureCurve* BlinkPlatformImpl::createFlingAnimationCurve(
       cumulative_scroll);
 #endif
 
-  if (device_source == blink::WebGestureDeviceTouchscreen)
-    return fling_curve_configuration_->CreateForTouchScreen(velocity,
-                                                            cumulative_scroll);
-
-  return fling_curve_configuration_->CreateForTouchPad(velocity,
-                                                       cumulative_scroll);
+  return TouchFlingGestureCurve::Create(velocity, cumulative_scroll);
 }
 
 void BlinkPlatformImpl::didStartWorkerRunLoop(
@@ -1184,12 +1178,6 @@ size_t BlinkPlatformImpl::maxDecodedImageBytes() {
 #endif
 }
 
-void BlinkPlatformImpl::SetFlingCurveParameters(
-    const std::vector<float>& new_touchpad,
-    const std::vector<float>& new_touchscreen) {
-  fling_curve_configuration_->SetCurveParameters(new_touchpad, new_touchscreen);
-}
-
 void BlinkPlatformImpl::SuspendSharedTimer() {
   ++shared_timer_suspended_;
 }
diff --git a/content/child/blink_platform_impl.h b/content/child/blink_platform_impl.h
index b39f1f8..65d4239 100644
--- a/content/child/blink_platform_impl.h
+++ b/content/child/blink_platform_impl.h
@@ -154,9 +154,6 @@ class CONTENT_EXPORT BlinkPlatformImpl
       const blink::WebWorkerRunLoop& runLoop) OVERRIDE;
   virtual blink::WebCrypto* crypto() OVERRIDE;
 
-  void SetFlingCurveParameters(const std::vector<float>& new_touchpad,
-                               const std::vector<float>& new_touchscreen);
-
   void SuspendSharedTimer();
   void ResumeSharedTimer();
   virtual void OnStartSharedTimer(base::TimeDelta delay) {}
@@ -177,7 +174,6 @@ class CONTENT_EXPORT BlinkPlatformImpl
   double shared_timer_fire_time_;
   bool shared_timer_fire_time_was_set_while_suspended_;
   int shared_timer_suspended_;  // counter
-  scoped_ptr<FlingCurveConfiguration> fling_curve_configuration_;
   base::ThreadLocalStorage::Slot current_thread_slot_;
   WebCryptoImpl web_crypto_;
 };
diff --git a/content/child/fling_curve_configuration.cc b/content/child/fling_curve_configuration.cc
deleted file mode 100644
index 8beeb36..0000000
--- a/content/child/fling_curve_configuration.cc
+++ /dev/null
@@ -1,56 +0,0 @@
-// Copyright 2014 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/child/fling_curve_configuration.h"
-
-#include "base/logging.h"
-#include "content/child/touch_fling_gesture_curve.h"
-#include "third_party/WebKit/public/platform/WebGestureCurve.h"
-
-namespace content {
-
-FlingCurveConfiguration::FlingCurveConfiguration() { }
-
-FlingCurveConfiguration::~FlingCurveConfiguration() { }
-
-void FlingCurveConfiguration::SetCurveParameters(
-    const std::vector<float>& new_touchpad,
-    const std::vector<float>& new_touchscreen) {
-  DCHECK(new_touchpad.size() >= 3);
-  DCHECK(new_touchscreen.size() >= 3);
-  base::AutoLock scoped_lock(lock_);
-  touchpad_coefs_ = new_touchpad;
-  touchscreen_coefs_ = new_touchscreen;
-}
-
-blink::WebGestureCurve* FlingCurveConfiguration::CreateCore(
-    const std::vector<float>& coefs,
-    const blink::WebFloatPoint& velocity,
-    const blink::WebSize& cumulativeScroll) {
-  float p0, p1, p2;
-
-  {
-    base::AutoLock scoped_lock(lock_);
-    p0 = coefs[0];
-    p1 = coefs[1];
-    p2 = coefs[2];
-  }
-
-  return TouchFlingGestureCurve::Create(velocity, p0, p1, p2,
-      cumulativeScroll);
-}
-
-blink::WebGestureCurve* FlingCurveConfiguration::CreateForTouchPad(
-    const blink::WebFloatPoint& velocity,
-    const blink::WebSize& cumulativeScroll) {
-  return CreateCore(touchpad_coefs_, velocity, cumulativeScroll);
-}
-
-blink::WebGestureCurve* FlingCurveConfiguration::CreateForTouchScreen(
-    const blink::WebFloatPoint& velocity,
-    const blink::WebSize& cumulativeScroll) {
-  return CreateCore(touchscreen_coefs_, velocity, cumulativeScroll);
-}
-
-} // namespace content
diff --git a/content/child/fling_curve_configuration.h b/content/child/fling_curve_configuration.h
deleted file mode 100644
index 1a6573d..0000000
--- a/content/child/fling_curve_configuration.h
+++ /dev/null
@@ -1,58 +0,0 @@
-// Copyright 2014 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.
-
-#ifndef CONTENT_CHILD_FLING_CURVE_CONFIGURATION_H_
-#define CONTENT_CHILD_FLING_CURVE_CONFIGURATION_H_
-
-#include <vector>
-
-#include "base/synchronization/lock.h"
-#include "third_party/WebKit/public/platform/WebFloatPoint.h"
-#include "third_party/WebKit/public/platform/WebSize.h"
-
-namespace blink {
-class WebGestureCurve;
-}
-
-namespace content {
-
-// A class to manage dynamically adjustable parameters controlling the
-// shape of the fling deacceleration function.
-class FlingCurveConfiguration {
- public:
-  FlingCurveConfiguration();
-  virtual ~FlingCurveConfiguration();
-
-  // Create a touchpad fling curve using the current parameters.
-  blink::WebGestureCurve* CreateForTouchPad(
-      const blink::WebFloatPoint& velocity,
-      const blink::WebSize& cumulativeScroll);
-
-  // Create a touchscreen fling curve using the current parameters.
-  blink::WebGestureCurve* CreateForTouchScreen(
-      const blink::WebFloatPoint& velocity,
-      const blink::WebSize& cumulativeScroll);
-
-  // Set the curve parameters.
-  void SetCurveParameters(
-      const std::vector<float>& new_touchpad,
-      const std::vector<float>& new_touchscreen);
-
- private:
-  blink::WebGestureCurve* CreateCore(
-    const std::vector<float>& coefs,
-    const blink::WebFloatPoint& velocity,
-    const blink::WebSize& cumulativeScroll);
-
-  // Protect access to touchpad_coefs_ and touchscreen_coefs_.
-  base::Lock lock_;
-  std::vector<float> touchpad_coefs_;
-  std::vector<float> touchscreen_coefs_;
-
-  DISALLOW_COPY_AND_ASSIGN(FlingCurveConfiguration);
-};
-
-} // namespace content
-
-#endif // CONTENT_CHILD_FLING_CURVE_CONFIGURATION_H_
diff --git a/content/child/touch_fling_gesture_curve.cc b/content/child/touch_fling_gesture_curve.cc
index cc94bd6..c871458 100644
--- a/content/child/touch_fling_gesture_curve.cc
+++ b/content/child/touch_fling_gesture_curve.cc
@@ -24,18 +24,27 @@ namespace {
 
 const char* kCurveName = "TouchFlingGestureCurve";
 
-inline double position(double t, float* p) {
-  return p[0] * exp(-p[2] * t) - p[1] * t - p[0];
+// The touchpad / touchscreen fling profiles are a matched set
+// determined via UX experimentation. Do not modify without
+// first discussing with rjkroege@chromium.org or
+// wjmaclean@chromium.org.
+const float kDefaultAlpha = -5.70762e+03f;
+const float kDefaultBeta = 1.72e+02f;
+const float kDefaultGamma = 3.7e+00f;
+
+inline double position(double t) {
+  return kDefaultAlpha * exp(-kDefaultGamma * t) - kDefaultBeta * t -
+         kDefaultAlpha;
 }
 
-inline double velocity(double t, float* p) {
-  return -p[0] * p[2] * exp(-p[2] * t) - p[1];
+inline double velocity(double t) {
+  return -kDefaultAlpha * kDefaultGamma * exp(-kDefaultGamma * t) -
+         kDefaultBeta;
 }
 
-inline double timeAtVelocity(double v, float* p) {
-    DCHECK(p[0]);
-    DCHECK(p[2]);
-    return -log((v + p[1]) / (-p[0] * p[2])) / p[2];
+inline double timeAtVelocity(double v) {
+  return -log((v + kDefaultBeta) / (-kDefaultAlpha * kDefaultGamma)) /
+         kDefaultGamma;
 }
 
 } // namespace
@@ -68,30 +77,19 @@ namespace content {
 
 WebGestureCurve* TouchFlingGestureCurve::Create(
     const WebFloatPoint& initial_velocity,
-    float p0,
-    float p1,
-    float p2,
     const WebSize& cumulative_scroll) {
-  return new TouchFlingGestureCurve(initial_velocity, p0, p1, p2,
-                                    cumulative_scroll);
+  return new TouchFlingGestureCurve(initial_velocity, cumulative_scroll);
 }
 
 TouchFlingGestureCurve::TouchFlingGestureCurve(
     const WebFloatPoint& initial_velocity,
-    float alpha,
-    float beta,
-    float gamma,
     const WebSize& cumulative_scroll)
     : cumulative_scroll_(WebFloatSize(cumulative_scroll.width,
                                       cumulative_scroll.height)) {
   DCHECK(initial_velocity != WebFloatPoint());
 
-  coefficients_[0] = alpha;
-  coefficients_[1] = beta;
-  coefficients_[2] = gamma;
-
   // Curve ends when velocity reaches zero.
-  curve_duration_ = timeAtVelocity(0, coefficients_);
+  curve_duration_ = timeAtVelocity(0);
   DCHECK(curve_duration_ > 0);
 
   float max_start_velocity = std::max(fabs(initial_velocity.x),
@@ -100,8 +98,8 @@ TouchFlingGestureCurve::TouchFlingGestureCurve(
   // Force max_start_velocity to lie in the range v(0) to v(curve_duration),
   // and assume that the curve parameters define a monotonically decreasing
   // velocity, or else bisection search may fail.
-  if (max_start_velocity > velocity(0, coefficients_))
-    max_start_velocity = velocity(0, coefficients_);
+  if (max_start_velocity > velocity(0))
+    max_start_velocity = velocity(0);
 
   if (max_start_velocity < 0)
     max_start_velocity = 0;
@@ -112,10 +110,10 @@ TouchFlingGestureCurve::TouchFlingGestureCurve(
                                       initial_velocity.y / max_start_velocity);
 
   // Compute time-offset for start velocity.
-  time_offset_ = timeAtVelocity(max_start_velocity, coefficients_);
+  time_offset_ = timeAtVelocity(max_start_velocity);
 
   // Compute curve position at offset time
-  position_offset_ = position(time_offset_, coefficients_);
+  position_offset_ = position(time_offset_);
   TRACE_EVENT_ASYNC_BEGIN1("input", "GestureAnimation", this, "curve",
       kCurveName);
 }
@@ -133,11 +131,10 @@ bool TouchFlingGestureCurve::apply(double time, WebGestureCurveTarget* target) {
   float displacement;
   float speed;
   if (time + time_offset_ < curve_duration_) {
-    displacement =
-        position(time + time_offset_, coefficients_) - position_offset_;
-    speed = velocity(time + time_offset_, coefficients_);
+    displacement = position(time + time_offset_) - position_offset_;
+    speed = velocity(time + time_offset_);
   } else {
-    displacement = position(curve_duration_, coefficients_) - position_offset_;
+    displacement = position(curve_duration_) - position_offset_;
     speed = 0.f;
   }
 
diff --git a/content/child/touch_fling_gesture_curve.h b/content/child/touch_fling_gesture_curve.h
index 555fc74..d8c4495 100644
--- a/content/child/touch_fling_gesture_curve.h
+++ b/content/child/touch_fling_gesture_curve.h
@@ -26,7 +26,6 @@ class TouchFlingGestureCurve : public blink::WebGestureCurve {
 
   static CONTENT_EXPORT WebGestureCurve* Create(
       const blink::WebFloatPoint& initial_velocity,
-      float p0, float p1, float p2,
       const blink::WebSize& cumulativeScroll);
 
  virtual bool apply(double monotonicTime,
@@ -34,15 +33,11 @@ class TouchFlingGestureCurve : public blink::WebGestureCurve {
 
  private:
   TouchFlingGestureCurve(const blink::WebFloatPoint& initial_velocity,
-                         float p0,
-                         float p1,
-                         float p2,
                          const blink::WebSize& cumulativeScroll);
   virtual ~TouchFlingGestureCurve();
 
   blink::WebFloatPoint displacement_ratio_;
   blink::WebFloatSize cumulative_scroll_;
-  float coefficients_[3];
   float time_offset_;
   float curve_duration_;
   float position_offset_;
diff --git a/content/child/touch_fling_gesture_curve_unittest.cc b/content/child/touch_fling_gesture_curve_unittest.cc
index 9c42e63..971c263 100644
--- a/content/child/touch_fling_gesture_curve_unittest.cc
+++ b/content/child/touch_fling_gesture_curve_unittest.cc
@@ -50,8 +50,7 @@ TEST(TouchFlingGestureCurve, flingCurveTouch)
   MockGestureCurveTarget target;
 
   scoped_ptr<WebGestureCurve> curve(content::TouchFlingGestureCurve::Create(
-      WebFloatPoint(initialVelocity, 0),
-      -5.70762e+03f, 1.72e+02f, 3.7e+00f, WebSize()));
+      WebFloatPoint(initialVelocity, 0), WebSize()));
 
   // Note: the expectations below are dependent on the curve parameters hard
   // coded into the create call above.
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 373a3f1..ed50c60 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -208,8 +208,6 @@ IPC_STRUCT_TRAITS_BEGIN(content::RendererPreferences)
   IPC_STRUCT_TRAITS_MEMBER(user_agent_override)
   IPC_STRUCT_TRAITS_MEMBER(accept_languages)
   IPC_STRUCT_TRAITS_MEMBER(report_frame_name_changes)
-  IPC_STRUCT_TRAITS_MEMBER(touchpad_fling_profile)
-  IPC_STRUCT_TRAITS_MEMBER(touchscreen_fling_profile)
   IPC_STRUCT_TRAITS_MEMBER(tap_multiple_targets_strategy)
   IPC_STRUCT_TRAITS_MEMBER(disable_client_blocked_error_page)
   IPC_STRUCT_TRAITS_MEMBER(plugin_fullscreen_allowed)
diff --git a/content/content_child.gypi b/content/content_child.gypi
index 9a4b411..e4f7b58 100644
--- a/content/content_child.gypi
+++ b/content/content_child.gypi
@@ -70,8 +70,6 @@
       'child/fileapi/webfilewriter_impl.h',
       'child/fling_animator_impl_android.cc',
       'child/fling_animator_impl_android.h',
-      'child/fling_curve_configuration.cc',
-      'child/fling_curve_configuration.h',
       'child/ftp_directory_listing_response_delegate.cc',
       'child/ftp_directory_listing_response_delegate.h',
       'child/image_decoder.cc',
diff --git a/content/public/common/renderer_preferences.cc b/content/public/common/renderer_preferences.cc
index 584b2e8..a43b9439 100644
--- a/content/public/common/renderer_preferences.cc
+++ b/content/public/common/renderer_preferences.cc
@@ -7,16 +7,6 @@
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/font_render_params.h"
 
-namespace {
-// The touchpad / touchscreen fling profiles are a matched set
-// determined via UX experimentation. Do not modify without
-// first discussing with rjkroege@chromium.org or
-// wjmaclean@chromium.org.
-const float kDefaultAlpha = -5.70762e+03f;
-const float kDefaultBeta = 1.72e+02f;
-const float kDefaultGamma = 3.7e+00f;
-}
-
 namespace content {
 
 RendererPreferences::RendererPreferences()
@@ -43,16 +33,10 @@ RendererPreferences::RendererPreferences()
       enable_do_not_track(false),
       default_zoom_level(0),
       report_frame_name_changes(false),
-      touchpad_fling_profile(3),
-      touchscreen_fling_profile(3),
       tap_multiple_targets_strategy(TAP_MULTIPLE_TARGETS_STRATEGY_POPUP),
       disable_client_blocked_error_page(false),
       plugin_fullscreen_allowed(true),
       use_video_overlay_for_embedded_encrypted_video(false) {
-  touchpad_fling_profile[0] = kDefaultAlpha;
-  touchpad_fling_profile[1] = kDefaultBeta;
-  touchpad_fling_profile[2] = kDefaultGamma;
-  touchscreen_fling_profile = touchpad_fling_profile;
 }
 
 RendererPreferences::~RendererPreferences() { }
diff --git a/content/public/common/renderer_preferences.h b/content/public/common/renderer_preferences.h
index ce02b17..cb13db7 100644
--- a/content/public/common/renderer_preferences.h
+++ b/content/public/common/renderer_preferences.h
@@ -113,12 +113,6 @@ struct CONTENT_EXPORT RendererPreferences {
   // information.
   bool report_frame_name_changes;
 
-  // Controls deacceleration of touchpad-initiated flings.
-  std::vector<float> touchpad_fling_profile;
-
-  // Controls deacceleration of touchscreen-initiated flings.
-  std::vector<float> touchscreen_fling_profile;
-
   // How to handle a tap gesture touching multiple targets
   TapMultipleTargetsStrategy tap_multiple_targets_strategy;
 
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index ade02fb..9e2a309 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -1622,13 +1622,6 @@ RenderThreadImpl::GetMediaThreadTaskRunner() {
   return media_thread_->message_loop_proxy();
 }
 
-void RenderThreadImpl::SetFlingCurveParameters(
-    const std::vector<float>& new_touchpad,
-    const std::vector<float>& new_touchscreen) {
-  webkit_platform_support_->SetFlingCurveParameters(new_touchpad,
-                                                    new_touchscreen);
-}
-
 void RenderThreadImpl::SampleGamepads(blink::WebGamepads* data) {
   webkit_platform_support_->sampleGamepads(*data);
 }
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 1b91344..af82acc 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -383,9 +383,6 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
     return &histogram_customizer_;
   }
 
-  void SetFlingCurveParameters(const std::vector<float>& new_touchpad,
-                               const std::vector<float>& new_touchscreen);
-
   // Retrieve current gamepad data.
   void SampleGamepads(blink::WebGamepads* data);
 
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index adc15a9..200a2a1 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -3092,11 +3092,6 @@ void RenderViewImpl::OnSetRendererPrefs(
   }
 #endif  // defined(USE_DEFAULT_RENDER_THEME)
 
-  if (RenderThreadImpl::current())  // Will be NULL during unit tests.
-    RenderThreadImpl::current()->SetFlingCurveParameters(
-        renderer_prefs.touchpad_fling_profile,
-        renderer_prefs.touchscreen_fling_profile);
-
   // If the zoom level for this page matches the old zoom default, and this
   // is not a plugin, update the zoom level to match the new default.
   if (webview() && webview()->mainFrame()->isWebLocalFrame() &&
diff --git a/ui/aura/test/aura_test_base.cc b/ui/aura/test/aura_test_base.cc
index 39064fb..039661d 100644
--- a/ui/aura/test/aura_test_base.cc
+++ b/ui/aura/test/aura_test_base.cc
@@ -51,14 +51,6 @@ void AuraTestBase::SetUp() {
   ui::GestureConfiguration::set_min_distance_for_pinch_scroll_in_pixels(20);
   ui::GestureConfiguration::set_min_pinch_update_distance_in_pixels(5);
   ui::GestureConfiguration::set_default_radius(0);
-  ui::GestureConfiguration::set_fling_acceleration_curve_coefficients(
-      0, 0.0166667f);
-  ui::GestureConfiguration::set_fling_acceleration_curve_coefficients(
-      1, -0.0238095f);
-  ui::GestureConfiguration::set_fling_acceleration_curve_coefficients(
-      2, 0.0452381f);
-  ui::GestureConfiguration::set_fling_acceleration_curve_coefficients(
-      3, 0.8f);
   ui::GestureConfiguration::set_fling_velocity_cap(15000.0f);
   ui::GestureConfiguration::set_min_swipe_speed(10);
 
diff --git a/ui/events/gestures/gesture_configuration.cc b/ui/events/gestures/gesture_configuration.cc
index dd6188d..1ce13d7 100644
--- a/ui/events/gestures/gesture_configuration.cc
+++ b/ui/events/gestures/gesture_configuration.cc
@@ -40,15 +40,4 @@ int GestureConfiguration::scroll_debounce_interval_in_ms_ = 30;
 int GestureConfiguration::scroll_debounce_interval_in_ms_ = 0;
 #endif
 
-// Coefficients for a function that computes fling acceleration.
-// These are empirically determined defaults. Do not adjust without
-// additional empirical validation.
-float GestureConfiguration::fling_acceleration_curve_coefficients_[
-    NumAccelParams] = {
-  0.0166667f,
-  -0.0238095f,
-  0.0452381f,
-  0.8f
-};
-
 }  // namespace ui
diff --git a/ui/events/gestures/gesture_configuration.h b/ui/events/gestures/gesture_configuration.h
index 39b3054..1537b8e 100644
--- a/ui/events/gestures/gesture_configuration.h
+++ b/ui/events/gestures/gesture_configuration.h
@@ -16,10 +16,6 @@ namespace ui {
 
 class EVENTS_BASE_EXPORT GestureConfiguration {
  public:
-  // Number of parameters in the array of parameters for the fling acceleration
-  // curve.
-  static const int NumAccelParams = 4;
-
   // Ordered alphabetically ignoring underscores, to align with the
   // associated list of prefs in gesture_prefs_aura.cc.
   static int default_radius() {
@@ -134,12 +130,6 @@ class EVENTS_BASE_EXPORT GestureConfiguration {
   static int set_scroll_debounce_interval_in_ms(int val) {
     return scroll_debounce_interval_in_ms_ = val;
   }
-  static void set_fling_acceleration_curve_coefficients(int i, float val) {
-    fling_acceleration_curve_coefficients_[i] = val;
-  }
-  static float fling_acceleration_curve_coefficients(int i) {
-    return fling_acceleration_curve_coefficients_[i];
-  }
   static float fling_velocity_cap() {
     return fling_velocity_cap_;
   }
@@ -192,7 +182,6 @@ class EVENTS_BASE_EXPORT GestureConfiguration {
   static int min_scaling_span_in_pixels_;
   static int show_press_delay_in_ms_;
   static int scroll_debounce_interval_in_ms_;
-  static float fling_acceleration_curve_coefficients_[NumAccelParams];
   static float fling_velocity_cap_;
   // TODO(davemoore): Move into chrome/browser/ui.
   static int tab_scrub_activation_delay_in_ms_;