Optimization: avoid making 4 JNI calls to get touch device attributes.

ui/base/touch/touch_device_linux.cc

 // Copyright (c) 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 "ui/base/touch/touch_device.h"
 
 #include "base/logging.h"
 #include "ui/events/devices/input_device_manager.h"
 
 namespace ui {
 
 namespace {
 
 bool IsTouchDevicePresent() {
   return !InputDeviceManager::GetInstance()->GetTouchscreenDevices().empty();
 }
 
+// TODO(mustaq@chromium.org): Use mouse detection logic. crbug.com/495634
+int GetAvailablePointerTypes() {
+  // Assume a mouse is there
+  int available_pointer_types = POINTER_TYPE_FINE;
+  if (IsTouchDevicePresent())
+    available_pointer_types |= POINTER_TYPE_COARSE;
+
+  DCHECK(available_pointer_types);
+  return available_pointer_types;
+}
+
+// TODO(mustaq@chromium.org): Use mouse detection logic. crbug.com/495634
+int GetAvailableHoverTypes() {
+  // Assume a mouse is there
+  int available_hover_types = HOVER_TYPE_HOVER;
+  if (IsTouchDevicePresent())
+    available_hover_types |= HOVER_TYPE_ON_DEMAND;
+
+  DCHECK(available_hover_types);
+  return available_hover_types;
+}
+
 }  // namespace
 
 TouchScreensAvailability GetTouchScreensAvailability() {
   if (!IsTouchDevicePresent())
     return TouchScreensAvailability::NONE;
 
   return InputDeviceManager::GetInstance()->AreTouchscreensEnabled()
              ? TouchScreensAvailability::ENABLED
              : TouchScreensAvailability::DISABLED;
 }
 
 int MaxTouchPoints() {
   int max_touch = 0;
   const std::vector<ui::TouchscreenDevice>& touchscreen_devices =
       ui::InputDeviceManager::GetInstance()->GetTouchscreenDevices();
   for (const ui::TouchscreenDevice& device : touchscreen_devices) {
     if (device.touch_points > max_touch)
       max_touch = device.touch_points;
   }
   return max_touch;
 }
 
-// TODO(mustaq@chromium.org): Use mouse detection logic. crbug.com/495634
-int GetAvailablePointerTypes() {
-  // Assume a mouse is there
-  int available_pointer_types = POINTER_TYPE_FINE;
-  if (IsTouchDevicePresent())
-    available_pointer_types |= POINTER_TYPE_COARSE;
-
-  DCHECK(available_pointer_types);
-  return available_pointer_types;
+std::pair<int, int> GetAvailablePointerAndHoverTypes() {
+  return std::make_pair(GetAvailablePointerTypes(), GetAvailableHoverTypes());
 }
 
-PointerType GetPrimaryPointerType() {
-  int available_pointer_types = GetAvailablePointerTypes();
+PointerType GetPrimaryPointerType(int available_pointer_types) {
   if (available_pointer_types & POINTER_TYPE_FINE)
     return POINTER_TYPE_FINE;
   if (available_pointer_types & POINTER_TYPE_COARSE)
     return POINTER_TYPE_COARSE;
   DCHECK_EQ(available_pointer_types, POINTER_TYPE_NONE);
   return POINTER_TYPE_NONE;
 }
 
-// TODO(mustaq@chromium.org): Use mouse detection logic. crbug.com/495634
-int GetAvailableHoverTypes() {
-  // Assume a mouse is there
-  int available_hover_types = HOVER_TYPE_HOVER;
-  if (IsTouchDevicePresent())
-    available_hover_types |= HOVER_TYPE_ON_DEMAND;
-
-  DCHECK(available_hover_types);
-  return available_hover_types;
-}
-
-HoverType GetPrimaryHoverType() {
-  int available_hover_types = GetAvailableHoverTypes();
+HoverType GetPrimaryHoverType(int available_hover_types) {
   if (available_hover_types & HOVER_TYPE_HOVER)
     return HOVER_TYPE_HOVER;
   if (available_hover_types & HOVER_TYPE_ON_DEMAND)
     return HOVER_TYPE_ON_DEMAND;
   DCHECK_EQ(available_hover_types, HOVER_TYPE_NONE);
   return HOVER_TYPE_NONE;
 }
 
 }  // namespace ui