ui: Prefer emplace over insert.

Avoid potential unnecessary copies by using emplace consistently.

No intended functional changes.

Bug: 995605
Change-Id: I4e937338a05e6f7322d2813f2f633f0037cd4b67
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1761649Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Darwin Huang <huangdarwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688612}

ui/base/ime/chromeos/input_method_util_unittest.cc

@@ -306,10 +306,10 @@ TEST_F(InputMethodUtilTest, TestGetInputMethodDescriptorFromId) {
 
 TEST_F(InputMethodUtilTest, TestGetInputMethodIdsForLanguageCode) {
   std::multimap<std::string, std::string> language_code_to_ids_map;
-  language_code_to_ids_map.insert(std::make_pair("ja", pinyin_ime_id));
-  language_code_to_ids_map.insert(std::make_pair("ja", pinyin_ime_id));
-  language_code_to_ids_map.insert(std::make_pair("ja", "xkb:jp:jpn"));
-  language_code_to_ids_map.insert(std::make_pair("fr", "xkb:fr:fra"));
+  language_code_to_ids_map.emplace("ja", pinyin_ime_id);
+  language_code_to_ids_map.emplace("ja", pinyin_ime_id);
+  language_code_to_ids_map.emplace("ja", "xkb:jp:jpn");
+  language_code_to_ids_map.emplace("fr", "xkb:fr:fra");
 
   std::vector<std::string> result;
   EXPECT_TRUE(util_.GetInputMethodIdsFromLanguageCodeInternal(

ui/base/resource/data_pack.cc

@@ -486,11 +486,11 @@ bool DataPack::WritePack(const base::FilePath& path,
       auto it = rev_map.find(entry.second);
       if (it != rev_map.end()) {
         // Found an alias here!
-        aliases.insert(std::make_pair(entry.first, it->second));
+        aliases.emplace(entry.first, it->second);
       } else {
         // Found a final resource.
         const auto entry_index = static_cast<uint16_t>(resource_ids.size());
-        rev_map.insert(std::make_pair(entry.second, entry_index));
+        rev_map.emplace(entry.second, entry_index);
         resource_ids.push_back(entry.first);
       }
     }

ui/base/resource/data_pack_unittest.cc

@@ -216,11 +216,11 @@ TEST_P(DataPackTest, Write) {
   std::string fifteen("fifteen");
 
   std::map<uint16_t, base::StringPiece> resources;
-  resources.insert(std::make_pair(1, base::StringPiece(one)));
-  resources.insert(std::make_pair(2, base::StringPiece(two)));
-  resources.insert(std::make_pair(15, base::StringPiece(fifteen)));
-  resources.insert(std::make_pair(3, base::StringPiece(three)));
-  resources.insert(std::make_pair(4, base::StringPiece(four)));
+  resources.emplace(1, base::StringPiece(one));
+  resources.emplace(2, base::StringPiece(two));
+  resources.emplace(15, base::StringPiece(fifteen));
+  resources.emplace(3, base::StringPiece(three));
+  resources.emplace(4, base::StringPiece(four));
   ASSERT_TRUE(DataPack::WritePack(file, resources, GetParam()));
 
   // Now try to read the data back in.
@@ -256,13 +256,13 @@ TEST_P(DataPackTest, WriteWithAliases) {
   std::string fifteen("fifteen");
 
   std::map<uint16_t, base::StringPiece> resources;
-  resources.insert(std::make_pair(1, base::StringPiece(one)));
-  resources.insert(std::make_pair(2, base::StringPiece(two)));
-  resources.insert(std::make_pair(15, base::StringPiece(fifteen)));
-  resources.insert(std::make_pair(3, base::StringPiece(three)));
-  resources.insert(std::make_pair(4, base::StringPiece(four)));
-  resources.insert(std::make_pair(10, base::StringPiece(one)));
-  resources.insert(std::make_pair(11, base::StringPiece(three)));
+  resources.emplace(1, base::StringPiece(one));
+  resources.emplace(2, base::StringPiece(two));
+  resources.emplace(15, base::StringPiece(fifteen));
+  resources.emplace(3, base::StringPiece(three));
+  resources.emplace(4, base::StringPiece(four));
+  resources.emplace(10, base::StringPiece(one));
+  resources.emplace(11, base::StringPiece(three));
   ASSERT_TRUE(DataPack::WritePack(file, resources, GetParam()));
 
   // Now try to read the data back in.

ui/base/resource/resource_bundle.cc

@@ -563,7 +563,7 @@ gfx::Image& ResourceBundle::GetImageNamed(int resource_id) {
   }
 
   // The load was successful, so cache the image.
-  auto inserted = images_.insert(std::make_pair(resource_id, image));
+  auto inserted = images_.emplace(resource_id, image);
   DCHECK(inserted.second);
   return inserted.first->second;
 }
@@ -733,14 +733,14 @@ const gfx::FontList& ResourceBundle::GetFontListWithTypefaceAndDelta(
   // to the existing entry that the insertion collided with.
   const FontKey sized_key(typeface, size_delta, gfx::Font::NORMAL,
                           gfx::Font::Weight::NORMAL);
-  auto sized = font_cache_.insert(std::make_pair(sized_key, base_font_list));
+  auto sized = font_cache_.emplace(sized_key, base_font_list);
   if (sized.second)
     sized.first->second = base.DeriveWithSizeDelta(size_delta);
   if (styled_key == sized_key) {
     return sized.first->second;
   }
 
-  auto styled = font_cache_.insert(std::make_pair(styled_key, base_font_list));
+  auto styled = font_cache_.emplace(styled_key, base_font_list);
   DCHECK(styled.second);  // Otherwise font_cache_.find(..) would have found it.
   styled.first->second = sized.first->second.Derive(
       0, sized.first->second.GetFontStyle() | style, weight);

ui/base/resource/resource_bundle_ios.mm

@@ -167,7 +167,7 @@ gfx::Image& ResourceBundle::GetNativeImageNamed(int resource_id) {
 
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 
-  auto inserted = images_.insert(std::make_pair(resource_id, image));
+  auto inserted = images_.emplace(resource_id, image);
   DCHECK(inserted.second);
   return inserted.first->second;
 }

ui/base/resource/resource_bundle_mac.mm

@@ -139,7 +139,7 @@ gfx::Image& ResourceBundle::GetNativeImageNamed(int resource_id) {
 
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 
-  auto inserted = images_.insert(std::make_pair(resource_id, image));
+  auto inserted = images_.emplace(resource_id, image);
   DCHECK(inserted.second);
   return inserted.first->second;
 }

ui/base/x/selection_utils.cc

@@ -115,7 +115,7 @@ void SelectionFormatMap::Insert(
     ::Atom atom,
     const scoped_refptr<base::RefCountedMemory>& item) {
   data_.erase(atom);
-  data_.insert(std::make_pair(atom, item));
+  data_.emplace(atom, item);
 }
 
 ui::SelectionData SelectionFormatMap::GetFirstOf(

ui/display/mac/display_link_mac.cc

@@ -141,7 +141,7 @@ DisplayLinkMac::DisplayLinkMac(
     DPLOG_IF(ERROR, register_error != kCGErrorSuccess)
         << "CGDisplayRegisterReconfigurationCallback: " << register_error;
   }
-  all_display_links.insert(std::make_pair(display_id_, this));
+  all_display_links.emplace(display_id_, this);
 }
 
 DisplayLinkMac::~DisplayLinkMac() {

ui/display/win/screen_win_unittest.cc

@@ -162,7 +162,7 @@ class TestScreenWinManager final : public TestScreenWinInitializer {
 
   HWND CreateFakeHwnd(const gfx::Rect& bounds) override {
     EXPECT_EQ(screen_win_, nullptr);
-    hwnd_map_.insert(std::pair<HWND, gfx::Rect>(++hwndLast_, bounds));
+    hwnd_map_.emplace(++hwndLast_, bounds);
     return hwndLast_;
   }
 

ui/events/blink/prediction/filter_factory.cc

@@ -51,7 +51,7 @@ void FilterFactory::LoadFilterParams(
       FilterParamMapKey param_key = {FilterType::kOneEuro, predictor_type};
       FilterParams param_value = {{OneEuroFilter::kParamMincutoff, mincutoff},
                                   {OneEuroFilter::kParamBeta, beta}};
-      filter_params_map_.insert(std::make_pair(param_key, param_value));
+      filter_params_map_.emplace(param_key, param_value);
     }
   }
 }

ui/events/devices/x11/touch_factory_x11.cc

@@ -345,7 +345,7 @@ void TouchFactory::CacheTouchscreenIds(int device_id) {
                    });
   // Internal displays will have a vid and pid of 0. Ignore them.
   if (it != touchscreens.end() && it->vendor_id && it->product_id)
-    touchscreen_ids_.insert(std::make_pair(it->vendor_id, it->product_id));
+    touchscreen_ids_.emplace(it->vendor_id, it->product_id);
 }
 
 }  // namespace ui

ui/events/event_rewriter_unittest.cc

@@ -116,8 +116,7 @@ class TestStateMachineEventRewriterOld : public EventRewriter {
                EventType to_type,
                EventRewriteStatus to_status) {
     RewriteResult r = {to_state, to_type, to_status};
-    rules_.insert(std::pair<RewriteCase, RewriteResult>(
-        RewriteCase(from_state, from_type), r));
+    rules_.emplace(RewriteCase(from_state, from_type), r);
   }
   EventRewriteStatus RewriteEvent(
       const Event& event,

ui/gfx/image/image.cc

@@ -272,7 +272,7 @@ class ImageStorage : public base::RefCounted<ImageStorage> {
   const ImageRep* AddRepresentation(std::unique_ptr<ImageRep> rep) const {
     DCHECK(IsOnValidSequence());
     Image::RepresentationType type = rep->type();
-    auto result = representations_.insert(std::make_pair(type, std::move(rep)));
+    auto result = representations_.emplace(type, std::move(rep));
 
     // insert should not fail (implies that there was already a representation
     // of that type in the map).

ui/gfx/paint_vector_icon.cc

@@ -530,7 +530,7 @@ class VectorIconCache {
 
     ImageSkia icon_image(std::make_unique<VectorIconSource>(description),
                          Size(description.dip_size, description.dip_size));
-    images_.insert(std::make_pair(description, icon_image));
+    images_.emplace(description, icon_image);
     return icon_image;
   }
 

ui/gfx/sequential_id_generator.cc

@@ -39,8 +39,8 @@ uint32_t SequentialIDGenerator::GetGeneratedID(uint32_t number) {
     return find->second;
 
   int id = GetNextAvailableID();
-  number_to_id_.insert(std::make_pair(number, id));
-  id_to_number_.insert(std::make_pair(id, number));
+  number_to_id_.emplace(number, id);
+  id_to_number_.emplace(id, number);
   return id;
 }
 

ui/gfx/shadow_util.cc

@@ -90,8 +90,8 @@ const ShadowDetails& ShadowDetails::Get(int elevation, int corner_radius) {
   if (iter != g_shadow_cache.Get().end())
     return iter->second;
 
-  auto insertion = g_shadow_cache.Get().insert(std::make_pair(
-      std::make_pair(elevation, corner_radius), ShadowDetails()));
+  auto insertion = g_shadow_cache.Get().emplace(
+      std::make_pair(elevation, corner_radius), ShadowDetails());
   DCHECK(insertion.second);
   ShadowDetails* shadow = &insertion.first->second;
   shadow->values = ShadowValue::MakeMdShadowValues(elevation);

ui/gfx/x/x11_atom_cache.cc

@@ -271,7 +271,7 @@ XAtom X11AtomCache::GetAtom(const char* name) const {
     return it->second;
 
   XAtom atom = XInternAtom(xdisplay_, name, False);
-  cached_atoms_.insert(std::make_pair(name, atom));
+  cached_atoms_.emplace(name, atom);
   return atom;
 }
 

ui/gl/gl_egl_api_implementation.cc

@@ -95,9 +95,11 @@ const char* RealEGLApi::eglQueryStringFn(EGLDisplay dpy, EGLint name) {
   if (name == EGL_EXTENSIONS) {
     auto it = filtered_exts_.find(dpy);
     if (it == filtered_exts_.end()) {
-      it = filtered_exts_.insert(std::make_pair(
-          dpy, FilterGLExtensionList(EGLApiBase::eglQueryStringFn(dpy, name),
-                                     disabled_exts_))).first;
+      it = filtered_exts_
+               .emplace(dpy, FilterGLExtensionList(
+                                 EGLApiBase::eglQueryStringFn(dpy, name),
+                                 disabled_exts_))
+               .first;
     }
     return (*it).second.c_str();
   }

ui/message_center/popup_timers_controller.cc

@@ -54,7 +54,7 @@ void PopupTimersController::StartTimer(const std::string& id,
   std::unique_ptr<PopupTimer> timer(new PopupTimer(id, timeout, AsWeakPtr()));
 
   timer->Start();
-  popup_timers_.insert(std::make_pair(id, std::move(timer)));
+  popup_timers_.emplace(id, std::move(timer));
 }
 
 void PopupTimersController::StartAll() {

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

@@ -162,7 +162,7 @@ GbmSurfaceFactory::~GbmSurfaceFactory() {
 void GbmSurfaceFactory::RegisterSurface(gfx::AcceleratedWidget widget,
                                         GbmSurfaceless* surface) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  widget_to_surface_map_.insert(std::make_pair(widget, surface));
+  widget_to_surface_map_.emplace(widget, surface);
 }
 
 void GbmSurfaceFactory::UnregisterSurface(gfx::AcceleratedWidget widget) {

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

@@ -230,7 +230,7 @@ HardwareDisplayController* ScreenManager::GetDisplayController(
 void ScreenManager::AddWindow(gfx::AcceleratedWidget widget,
                               std::unique_ptr<DrmWindow> window) {
   std::pair<WidgetToWindowMap::iterator, bool> result =
-      window_map_.insert(std::make_pair(widget, std::move(window)));
+      window_map_.emplace(widget, std::move(window));
   DCHECK(result.second) << "Window already added.";
   UpdateControllerToWindowMapping();
 }

ui/ozone/platform/scenic/scenic_surface_factory.cc

@@ -165,7 +165,7 @@ void ScenicSurfaceFactory::AddSurface(gfx::AcceleratedWidget widget,
   base::AutoLock lock(surface_lock_);
   DCHECK(!base::Contains(surface_map_, widget));
   surface->AssertBelongsToCurrentThread();
-  surface_map_.insert(std::make_pair(widget, surface));
+  surface_map_.emplace(widget, surface);
 }
 
 void ScenicSurfaceFactory::RemoveSurface(gfx::AcceleratedWidget widget) {

ui/ozone/platform/wayland/gpu/wayland_buffer_manager_gpu.cc

@@ -80,7 +80,7 @@ void WaylandBufferManagerGpu::OnPresentation(
 
 void WaylandBufferManagerGpu::RegisterSurface(gfx::AcceleratedWidget widget,
                                               WaylandSurfaceGpu* surface) {
-  widget_to_surface_map_.insert(std::make_pair(widget, surface));
+  widget_to_surface_map_.emplace(widget, surface);
 }
 
 void WaylandBufferManagerGpu::UnregisterSurface(gfx::AcceleratedWidget widget) {

ui/ozone/platform/wayland/host/wayland_buffer_manager_host.cc

@@ -99,8 +99,8 @@ class WaylandBufferManagerHost::Surface {
   }
 
   bool CreateBuffer(const gfx::Size& size, uint32_t buffer_id) {
-    auto result = buffers_.insert(std::make_pair(
-        buffer_id, std::make_unique<WaylandBuffer>(size, buffer_id)));
+    auto result = buffers_.emplace(
+        buffer_id, std::make_unique<WaylandBuffer>(size, buffer_id));
     return result.second;
   }
 

ui/ozone/platform/wayland/host/wayland_zwp_linux_dmabuf.cc

@@ -74,7 +74,7 @@ void WaylandZwpLinuxDmabuf::CreateBuffer(base::ScopedFD fd,
   } else {
     // Store the |params| with the corresponding |callback| to identify newly
     // created buffer and notify the client about it via the |callback|.
-    pending_params_.insert(std::make_pair(params, std::move(callback)));
+    pending_params_.emplace(params, std::move(callback));
 
     zwp_linux_buffer_params_v1_add_listener(params, &params_listener, this);
     zwp_linux_buffer_params_v1_create(params, size.width(), size.height(),

ui/views/cocoa/native_widget_mac_ns_window_host.mm

@@ -302,7 +302,7 @@ NativeWidgetMacNSWindowHost::NativeWidgetMacNSWindowHost(NativeWidgetMac* owner)
       remote_ns_window_host_binding_(this) {
   DCHECK(GetIdToWidgetHostImplMap().find(widget_id_) ==
          GetIdToWidgetHostImplMap().end());
-  GetIdToWidgetHostImplMap().insert(std::make_pair(widget_id_, this));
+  GetIdToWidgetHostImplMap().emplace(widget_id_, this);
   DCHECK(owner);
 }