Use int32_t for duration property of toast

To match it with the API. Android and mojo API use 32bit int for this property.

BUG=none

Review-Url: https://codereview.chromium.org/2031973003
Cr-Commit-Position: refs/heads/master@{#397833}

ash/system/toast/toast_data.h

@@ -12,14 +12,12 @@
 namespace ash {
 
 struct ASH_EXPORT ToastData {
-  ToastData(const std::string& id,
-            const std::string& text,
-            uint64_t duration_ms)
+  ToastData(const std::string& id, const std::string& text, int32_t duration_ms)
       : id(id), text(text), duration_ms(duration_ms) {}
 
   std::string id;
   std::string text;
-  uint64_t duration_ms;
+  int32_t duration_ms;
 };
 
 }  // namespace ash

ash/system/toast/toast_manager.cc

@@ -13,7 +13,7 @@ namespace ash {
 namespace {
 
 // Minimum duration for a toast to be visible (in millisecond).
-uint64_t kMinimumDurationMs = 200;
+int32_t kMinimumDurationMs = 200;
 
 }  // anonymous namespace
 
@@ -72,7 +72,7 @@ void ToastManager::ShowLatest() {
   const ToastData data = std::move(queue_.front());
   queue_.pop_front();
 
-  uint64_t duration_ms = std::max(data.duration_ms, kMinimumDurationMs);
+  int32_t duration_ms = std::max(data.duration_ms, kMinimumDurationMs);
 
   current_toast_id_ = data.id;
   serial_++;

ash/system/toast/toast_manager_unittest.cc

@@ -16,7 +16,7 @@
 namespace ash {
 
 // Long duration so the timeout doesn't occur.
-const int64_t kLongLongDuration = INT64_MAX;
+const int32_t kLongLongDuration = INT32_MAX;
 
 class DummyEvent : public ui::Event {
  public:
@@ -76,7 +76,7 @@ class ToastManagerTest : public test::AshTestBase {
     Shelf::ForPrimaryDisplay()->SetAutoHideBehavior(behavior);
   }
 
-  std::string ShowToast(const std::string& text, uint64_t duration) {
+  std::string ShowToast(const std::string& text, int32_t duration) {
     std::string id = "TOAST_ID_" + base::UintToString(serial_++);
     manager()->Show(ToastData(id, text, duration));
     return id;