ime: Use new style enum for ImeSwitchType.

Use the new style for histogram enums [1]

[1] https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md#enum-histograms

TBR=sky@chromium.org

Bug: 953901
Change-Id: Icc8311ebfc17eac7a47113a0eb38259231ca1a95
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1621412
Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661589}
diff --git a/ash/accelerators/accelerator_controller_impl.cc b/ash/accelerators/accelerator_controller_impl.cc
index cffe64e..90a6450 100644
--- a/ash/accelerators/accelerator_controller_impl.cc
+++ b/ash/accelerators/accelerator_controller_impl.cc
@@ -208,7 +208,7 @@
 
 void RecordImeSwitchByAccelerator() {
   UMA_HISTOGRAM_ENUMERATION("InputMethod.ImeSwitch",
-                            ImeSwitchType::kAccelerator, ImeSwitchType::kCount);
+                            ImeSwitchType::kAccelerator);
 }
 
 void HandleCycleBackwardMRU(const ui::Accelerator& accelerator) {
diff --git a/ash/ime/ime_controller.cc b/ash/ime/ime_controller.cc
index 0e57214..3c906d7 100644
--- a/ash/ime/ime_controller.cc
+++ b/ash/ime/ime_controller.cc
@@ -244,8 +244,7 @@
     UMA_HISTOGRAM_ENUMERATION("InputMethod.ModeChangeKeyAction",
                               ModeChangeKeyAction::kSwitchIme);
     UMA_HISTOGRAM_ENUMERATION("InputMethod.ImeSwitch",
-                              ImeSwitchType::kModeChangeKey,
-                              ImeSwitchType::kCount);
+                              ImeSwitchType::kModeChangeKey);
   } else {
     client_->ShowModeIndicator();
 
diff --git a/ash/ime/ime_switch_type.h b/ash/ime/ime_switch_type.h
index f43af4d..6058092a 100644
--- a/ash/ime/ime_switch_type.h
+++ b/ash/ime/ime_switch_type.h
@@ -14,7 +14,7 @@
   kTray = 0,
   kAccelerator = 1,
   kModeChangeKey = 2,
-  kCount = 3,
+  kMaxValue = kModeChangeKey,
 };
 
 }  // namespace ash
diff --git a/ash/system/ime_menu/ime_list_view.cc b/ash/system/ime_menu/ime_list_view.cc
index 5bf5267..d621640 100644
--- a/ash/system/ime_menu/ime_list_view.cc
+++ b/ash/system/ime_menu/ime_list_view.cc
@@ -306,8 +306,7 @@
     std::string ime_id = ime->second;
     last_selected_item_id_ = ime_id;
     ime_controller->SwitchImeById(ime_id, false /* show_message */);
-    UMA_HISTOGRAM_ENUMERATION("InputMethod.ImeSwitch", ImeSwitchType::kTray,
-                              ImeSwitchType::kCount);
+    UMA_HISTOGRAM_ENUMERATION("InputMethod.ImeSwitch", ImeSwitchType::kTray);
 
   } else {
     std::map<views::View*, std::string>::const_iterator property =