Use container::back() and container::pop_back() in ui/

Also convert !container.size() to container.empty().

Review-Url: https://codereview.chromium.org/2126433002
Cr-Commit-Position: refs/heads/master@{#405289}

ui/base/ime/win/imm32_manager.cc

@@ -283,7 +283,8 @@ void IMM32Manager::CompleteComposition(HWND window_handle, HIMC imm_context) {
   }
 }
 
-void IMM32Manager::GetCompositionInfo(HIMC imm_context, LPARAM lparam,
+void IMM32Manager::GetCompositionInfo(HIMC imm_context,
+                                      LPARAM lparam,
                                       CompositionText* composition) {
   // We only care about GCS_COMPATTR, GCS_COMPCLAUSE and GCS_CURSORPOS, and
   // convert them into underlines and selection range respectively.
@@ -319,7 +320,9 @@ void IMM32Manager::GetCompositionInfo(HIMC imm_context, LPARAM lparam,
   }
 
   // Set default underlines in case there is no clause information.
-  if (!composition->underlines.size()) {
+  if (!composition->underlines.empty())
+    return;
+
   CompositionUnderline underline;
   underline.color = SK_ColorBLACK;
   underline.background_color = SK_ColorTRANSPARENT;
@@ -341,7 +344,6 @@ void IMM32Manager::GetCompositionInfo(HIMC imm_context, LPARAM lparam,
     underline.thick = false;
     composition->underlines.push_back(underline);
   }
-  }
 }
 
 bool IMM32Manager::GetString(HIMC imm_context,

ui/base/win/open_file_name_win_unittest.cc

@@ -19,7 +19,7 @@ void SetResult(const base::string16& result, ui::win::OpenFileName* ofn) {
     ADD_FAILURE() << "filename buffer insufficient.";
     return;
   }
-  if (!result.size()) {
+  if (result.empty()) {
     ofn->GetOPENFILENAME()->lpstrFile[0] = 0;
   } else {
     // Because the result has embedded nulls, we must memcpy.

ui/compositor/layer_animator_collection.cc

@@ -24,7 +24,7 @@ LayerAnimatorCollection::~LayerAnimatorCollection() {
 void LayerAnimatorCollection::StartAnimator(
     scoped_refptr<LayerAnimator> animator) {
   DCHECK_EQ(0U, animators_.count(animator));
-  if (!animators_.size())
+  if (animators_.empty())
     last_tick_time_ = base::TimeTicks::Now();
   animators_.insert(animator);
   if (animators_.size() == 1U && compositor_)

ui/display/mac/screen_mac.mm

@@ -262,10 +262,8 @@ class ScreenMac : public Screen {
       }
     }
 
-    if (!displays.size())
-      return std::vector<Display>(1, GetPrimaryDisplay());
-
-    return displays;
+    return displays.empty() ? std::vector<Display>(1, GetPrimaryDisplay())
+                            : displays;
   }
 
   // The displays currently attached to the device.

ui/events/ozone/evdev/libgestures_glue/event_reader_libevdev_cros.cc

@@ -20,8 +20,8 @@ namespace {
 
 std::string FormatLog(const char* fmt, va_list args) {
   std::string msg = base::StringPrintV(fmt, args);
-  if (!msg.empty() && msg[msg.size() - 1] == '\n')
-    msg.erase(msg.end() - 1, msg.end());
+  if (!msg.empty() && msg.back() == '\n')
+    msg.pop_back();
   return msg;
 }
 

ui/events/ozone/evdev/libgestures_glue/gesture_logging.cc

@@ -14,8 +14,8 @@ namespace {
 
 std::string FormatLog(const char* fmt, va_list args) {
   std::string msg = base::StringPrintV(fmt, args);
-  if (!msg.empty() && msg[msg.size() - 1] == '\n')
-    msg.erase(msg.end() - 1, msg.end());
+  if (!msg.empty() && msg.back() == '\n')
+    msg.pop_back();
   return msg;
 }
 

ui/events/ozone/evdev/libgestures_glue/gesture_property_provider.cc

@@ -1078,8 +1078,7 @@ void GesturePropertyProvider::ParseXorgConfFile(const std::string& content) {
         // one.
         if (is_parsing) {
           // Stop parsing the current line if the format is wrong.
-          if (piece.size() <= 2 || piece[0] != '\"' ||
-              piece[piece.size() - 1] != '\"') {
+          if (piece.size() <= 2 || piece[0] != '\"' || piece.back() != '\"') {
             LOG(ERROR) << "Error parsing line: " << lines.token();
             has_error = true;
             if (next_is_section_type)

ui/message_center/notification_list_unittest.cc

@@ -295,8 +295,8 @@ TEST_F(NotificationListTest, OldPopupShouldNotBeHidden) {
   }
   popups.clear();
   popups = GetPopups();
-  EXPECT_EQ(1u, popups.size());
-  EXPECT_EQ(ids[ids.size() - 1], (*popups.begin())->id());
+  ASSERT_EQ(1u, popups.size());
+  EXPECT_EQ(ids.back(), (*popups.begin())->id());
 }
 
 TEST_F(NotificationListTest, Priority) {

ui/message_center/popup_timers_controller.cc

@@ -96,7 +96,7 @@ void PopupTimersController::OnNotificationUpdated(const std::string& id) {
   NotificationList::PopupNotifications popup_notifications =
       message_center_->GetPopupNotifications();
 
-  if (!popup_notifications.size()) {
+  if (popup_notifications.empty()) {
     CancelAll();
     return;
   }

ui/message_center/views/notification_view.cc

@@ -95,7 +95,7 @@ std::unique_ptr<views::Border> MakeSeparatorBorder(int top,
 // message next to each other within a single column.
 class ItemView : public views::View {
  public:
-  ItemView(const message_center::NotificationItem& item);
+  explicit ItemView(const message_center::NotificationItem& item);
   ~ItemView() override;
 
   // Overridden from views::View:
@@ -435,7 +435,7 @@ void NotificationView::CreateOrUpdateMessageView(
     message_view_->SetText(text);
   }
 
-  message_view_->SetVisible(!notification.items().size());
+  message_view_->SetVisible(notification.items().empty());
 }
 
 base::string16 NotificationView::FormatContextMessage(
@@ -545,7 +545,7 @@ void NotificationView::CreateOrUpdateProgressBarView(
   if (!is_indeterminate)
     progress_bar_view_->SetValue(notification.progress() / 100.0);
 
-  progress_bar_view_->SetVisible(!notification.items().size());
+  progress_bar_view_->SetVisible(notification.items().empty());
 }
 
 void NotificationView::CreateOrUpdateListItemViews(

ui/ozone/platform/drm/gpu/drm_device.cc

@@ -278,7 +278,7 @@ std::vector<GammaRampRGBEntry> ResampleLut(
                     (lut_in[base_index + 1].b - lut_in[base_index].b) *
                         remaining / desired_size;
     } else {
-      result[i] = lut_in[lut_in.size() - 1];
+      result[i] = lut_in.back();
     }
   }
 
@@ -304,8 +304,7 @@ class DrmDevice::PageFlipManager {
     }
 
     DrmDevice::PageFlipCallback callback = it->callback;
-    it->pending_calls -= 1;
-
+    it->pending_calls--;
     if (it->pending_calls)
       return;
 
@@ -329,11 +328,11 @@ class DrmDevice::PageFlipManager {
   };
 
   struct FindCallback {
-    FindCallback(uint64_t id) : id(id) {}
+    explicit FindCallback(uint64_t id) : id(id) {}
 
     bool operator()(const PageFlip& flip) const { return flip.id == id; }
 
-    uint64_t id;
+    const uint64_t id;
   };
 
   uint64_t next_id_;

ui/views/controls/textfield/textfield_model.cc

@@ -441,7 +441,7 @@ bool TextfieldModel::CanUndo() {
 }
 
 bool TextfieldModel::CanRedo() {
-  if (!edit_history_.size())
+  if (edit_history_.empty())
     return false;
   // There is no redo iff the current edit is the last element in the history.
   EditHistory::iterator iter = current_edit_;
@@ -464,7 +464,7 @@ bool TextfieldModel::Undo() {
   if (current_edit_ == edit_history_.begin())
     current_edit_ = edit_history_.end();
   else
-    current_edit_--;
+    --current_edit_;
   return old != text() || old_cursor != GetCursorPosition();
 }
 
@@ -478,7 +478,7 @@ bool TextfieldModel::Redo() {
   if (current_edit_ == edit_history_.end())
     current_edit_ = edit_history_.begin();
   else
-    current_edit_ ++;
+    ++current_edit_;
   base::string16 old = text();
   size_t old_cursor = GetCursorPosition();
   (*current_edit_)->Redo(this);
@@ -716,7 +716,7 @@ void TextfieldModel::ClearRedoHistory() {
     return;
   }
   EditHistory::iterator delete_start = current_edit_;
-  delete_start++;
+  ++delete_start;
   STLDeleteContainerPointers(delete_start, edit_history_.end());
   edit_history_.erase(delete_start, edit_history_.end());
 }
@@ -789,7 +789,7 @@ bool TextfieldModel::AddOrMergeEditHistory(Edit* edit) {
     DCHECK_EQ(1u, edit_history_.size());
     current_edit_ = edit_history_.begin();
   } else {
-    current_edit_++;
+    ++current_edit_;
   }
   return false;
 }

ui/views/layout/grid_layout.cc

@@ -937,8 +937,8 @@ void GridLayout::SizeRowsAndColumns(bool layout, int width, int height,
   LayoutElement::CalculateLocationsFromSize(&rows_);
 
   // We now know the preferred height, set it here.
-  pref->set_height(rows_[rows_.size() - 1]->Location() +
-      rows_[rows_.size() - 1]->Size() + insets_.height());
+  pref->set_height(rows_.back()->Location() + rows_.back()->Size() +
+                   insets_.height());
 
   if (layout && height != pref->height()) {
     // We're doing a layout, and the height differs from the preferred height,