[CodeHealth] Avoid unwanted copies with base::flat_{tree,set,map}<>

Applies one or more of the following:
-- std::move(argument) where possible.
-- remove stray 'const' where not helpful.
-- pass by const ref where helpful.
-- initalise in place to select for NRVO.

This CL was uploaded by git cl split.

browser/brave_shields/brave_shields_web_contents_observer.h

@@ -80,10 +80,6 @@ class BraveShieldsWebContentsObserver
   friend class content::WebContentsUserData<BraveShieldsWebContentsObserver>;
   friend class BraveShieldsWebContentsObserverBrowserTest;
 
-  using BraveShieldsRemotesMap = base::flat_map<
-      content::RenderFrameHost*,
-      mojo::AssociatedRemote<brave_shields::mojom::BraveShields>>;
-
   // Allows indicating a implementor of brave_shields::mojom::BraveShieldsHost
   // other than this own class, for testing purposes only.
   static void SetReceiverImplForTesting(BraveShieldsWebContentsObserver* impl);

browser/brave_wallet/brave_wallet_tab_helper.cc

@@ -37,33 +37,25 @@ BraveWalletTabHelper::~BraveWalletTabHelper() {
 void BraveWalletTabHelper::AddSolanaConnectedAccount(
     const content::GlobalRenderFrameHostId& id,
     const std::string& account) {
-  base::flat_set<std::string> connection_set;
-  if (solana_connected_accounts_.contains(id)) {
-    connection_set = solana_connected_accounts_.at(id);
-  }
-  connection_set.insert(account);
-  solana_connected_accounts_[id] = std::move(connection_set);
+  solana_connected_accounts_[id].insert(account);
 }
 
 void BraveWalletTabHelper::RemoveSolanaConnectedAccount(
     const content::GlobalRenderFrameHostId& id,
     const std::string& account) {
-  if (!solana_connected_accounts_.contains(id)) {
+  auto it = solana_connected_accounts_.find(id);
+  if (it == solana_connected_accounts_.end()) {
     return;
   }
-  auto connection_set = solana_connected_accounts_.at(id);
-  connection_set.erase(account);
-  solana_connected_accounts_[id] = std::move(connection_set);
+  it->second.erase(account);
 }
 
 bool BraveWalletTabHelper::IsSolanaAccountConnected(
     const content::GlobalRenderFrameHostId& id,
     const std::string& account) {
-  if (!solana_connected_accounts_.contains(id)) {
-    return false;
-  }
-  auto connection_set = solana_connected_accounts_.at(id);
-  return connection_set.contains(account);
+  auto it = solana_connected_accounts_.find(id);
+  return it == solana_connected_accounts_.end() ? false
+                                                : it->second.contains(account);
 }
 
 void BraveWalletTabHelper::ClearSolanaConnectedAccounts(

browser/ui/commands/accelerator_service.cc

@@ -83,7 +83,7 @@ AcceleratorService::AcceleratorService(
     base::flat_set<ui::Accelerator> system_managed)
     : pref_manager_(pref_service, commands::GetCommands()),
       default_accelerators_(std::move(default_accelerators)),
-      system_managed_(system_managed) {
+      system_managed_(std::move(system_managed)) {
   Initialize();
 }
 

browser/ui/commands/accelerator_service_factory.cc

@@ -54,8 +54,8 @@ KeyedService* AcceleratorServiceFactory::BuildServiceInstanceFor(
   DCHECK(profile);
 
   auto [accelerators, system_managed] = GetDefaultAccelerators();
-  return new AcceleratorService(profile->GetPrefs(), accelerators,
-                                system_managed);
+  return new AcceleratorService(profile->GetPrefs(), std::move(accelerators),
+                                std::move(system_managed));
 }
 
 }  // namespace commands

browser/ui/views/commands/default_accelerators_views.cc

@@ -4,11 +4,11 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 #include <utility>
+
 #include "base/containers/flat_set.h"
 #include "base/ranges/algorithm.h"
-#include "brave/browser/ui/commands/default_accelerators.h"
-
 #include "brave/browser/ui/commands/accelerator_service.h"
+#include "brave/browser/ui/commands/default_accelerators.h"
 #include "chrome/browser/ui/views/accelerator_table.h"
 #include "ui/base/accelerators/accelerator.h"
 
@@ -20,8 +20,8 @@ namespace commands {
 
 std::pair<Accelerators, base::flat_set<ui::Accelerator>>
 GetDefaultAccelerators() {
-  Accelerators defaults;
-  base::flat_set<ui::Accelerator> system_commands;
+  std::pair<Accelerators, base::flat_set<ui::Accelerator>> result;
+  auto& [defaults, system_commands] = result;
 
   auto add_to_accelerators = [&defaults](const AcceleratorMapping& mapping) {
     defaults[mapping.command_id].push_back(
@@ -39,7 +39,7 @@ GetDefaultAccelerators() {
                                mapping.keycode, mapping.modifiers));
                          });
 #endif  // BUILDFLAG(IS_MAC)
-  return std::tie(defaults, system_commands);
+  return result;
 }
 
 }  // namespace commands

build/ios/mojom/cpp_transformations.h

@@ -69,7 +69,7 @@ NS_INLINE NSArray<NSNumber*>* NSArrayFromVector(std::vector<T> v) {
   typedef NSNumber* (*NSNumberCall)(id, SEL, T);
   NSNumberCall call = (NSNumberCall)method_getImplementation(method);
 
-  for (auto t : v) {
+  for (const auto& t : v) {
     NSNumber* number =
         reinterpret_cast<NSNumber*>(call(NSNumber.class, selector, t));
     [a addObject:number];
@@ -102,7 +102,7 @@ NS_INLINE std::vector<T> VectorFromNSArray(NSArray<NSNumber*>* a) {
 /// Convert a vector storing strings to an array of NSString's
 NS_INLINE NSArray<NSString*>* NSArrayFromVector(std::vector<std::string> v) {
   const auto a = [NSMutableArray new];
-  for (auto s : v) {
+  for (const auto& s : v) {
     [a addObject:[NSString stringWithCString:s.c_str()
                                     encoding:NSUTF8StringEncoding]];
   }
@@ -175,12 +175,12 @@ NS_INLINE NSNumber* NumberFromPrimitive(T t) {
 /// NSNumber *>
 template <typename T>
 NS_INLINE NSDictionary<NSString*, NSNumber*>* NSDictionaryFromMap(
-    std::map<std::string, T> m) {
+    const std::map<std::string, T>& m) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[[NSString stringWithCString:item.first.c_str()
                          encoding:NSUTF8StringEncoding]] =
         NumberFromPrimitive(item.second);
@@ -192,12 +192,12 @@ NS_INLINE NSDictionary<NSString*, NSNumber*>* NSDictionaryFromMap(
 /// NSNumber *>
 template <typename T>
 NS_INLINE NSDictionary<NSString*, NSNumber*>* NSDictionaryFromMap(
-    base::flat_map<std::string, T> m) {
+    const base::flat_map<std::string, T>& m) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[[NSString stringWithCString:item.first.c_str()
                          encoding:NSUTF8StringEncoding]] =
         NumberFromPrimitive(item.second);
@@ -207,12 +207,12 @@ NS_INLINE NSDictionary<NSString*, NSNumber*>* NSDictionaryFromMap(
 
 /// Convert a String to String mapping to an NSDictionary
 NS_INLINE NSDictionary<NSString*, NSString*>* NSDictionaryFromMap(
-    std::map<std::string, std::string> m) {
+    const std::map<std::string, std::string>& m) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[[NSString stringWithCString:item.first.c_str()
                          encoding:NSUTF8StringEncoding]] =
         [NSString stringWithCString:item.second.c_str()
@@ -223,12 +223,12 @@ NS_INLINE NSDictionary<NSString*, NSString*>* NSDictionaryFromMap(
 
 /// Convert a String to String mapping to an NSDictionary
 NS_INLINE NSDictionary<NSString*, NSString*>* NSDictionaryFromMap(
-    base::flat_map<std::string, std::string> m) {
+    const base::flat_map<std::string, std::string>& m) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[[NSString stringWithCString:item.first.c_str()
                          encoding:NSUTF8StringEncoding]] =
         [NSString stringWithCString:item.second.c_str()
@@ -241,13 +241,13 @@ NS_INLINE NSDictionary<NSString*, NSString*>* NSDictionaryFromMap(
 /// objects
 template <typename V, typename ObjCObj>
 NS_INLINE NSDictionary<NSString*, ObjCObj>* NSDictionaryFromMap(
-    std::map<std::string, V> m,
+    const std::map<std::string, V>& m,
     ObjCObj (^transformValue)(V)) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[[NSString stringWithCString:item.first.c_str()
                          encoding:NSUTF8StringEncoding]] =
         transformValue(item.second);
@@ -259,13 +259,13 @@ NS_INLINE NSDictionary<NSString*, ObjCObj>* NSDictionaryFromMap(
 /// objects
 template <typename V, typename ObjCObj>
 NS_INLINE NSDictionary<NSString*, ObjCObj>* NSDictionaryFromMap(
-    base::flat_map<std::string, V> m,
+    const base::flat_map<std::string, V>& m,
     ObjCObj (^transformValue)(V)) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[[NSString stringWithCString:item.first.c_str()
                          encoding:NSUTF8StringEncoding]] =
         transformValue(item.second);
@@ -277,14 +277,14 @@ NS_INLINE NSDictionary<NSString*, ObjCObj>* NSDictionaryFromMap(
 /// the key and the value types to Obj-C types
 template <typename K, typename KObjC, typename V, typename VObjC>
 NS_INLINE NSDictionary<KObjC, VObjC>* NSDictionaryFromMap(
-    std::map<K, V> m,
+    const std::map<K, V>& m,
     KObjC (^transformKey)(K),
     VObjC (^transformValue)(V)) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[transformKey(item.first)] = transformValue(item.second);
   }
   return d;
@@ -294,14 +294,14 @@ NS_INLINE NSDictionary<KObjC, VObjC>* NSDictionaryFromMap(
 /// the key and the value types to Obj-C types
 template <typename K, typename KObjC, typename V, typename VObjC>
 NS_INLINE NSDictionary<KObjC, VObjC>* NSDictionaryFromMap(
-    base::flat_map<K, V> m,
+    const base::flat_map<K, V>& m,
     KObjC (^transformKey)(K),
     VObjC (^transformValue)(V)) {
   const auto d = [NSMutableDictionary new];
   if (m.empty()) {
     return @{};
   }
-  for (auto item : m) {
+  for (const auto& item : m) {
     d[transformKey(item.first)] = transformValue(item.second);
   }
   return d;

components/ai_chat/content/browser/page_content_fetcher.cc

@@ -290,7 +290,6 @@ class PageContentFetcherInternal {
       std::string invalidation_token,
       std::unique_ptr<std::string> response_body) {
     auto response_code = -1;
-    base::flat_map<std::string, std::string> headers;
     if (loader->ResponseInfo()) {
       auto headers_list = loader->ResponseInfo()->headers;
       if (headers_list) {
@@ -328,7 +327,6 @@ class PageContentFetcherInternal {
                             std::unique_ptr<network::SimpleURLLoader> loader,
                             std::unique_ptr<std::string> response_body) {
     auto response_code = -1;
-    base::flat_map<std::string, std::string> headers;
     if (loader->ResponseInfo()) {
       auto headers_list = loader->ResponseInfo()->headers;
       if (headers_list) {

components/ai_chat/core/browser/engine/engine_consumer_claude.cc

@@ -167,8 +167,8 @@ EngineConsumerClaudeRemote::EngineConsumerClaudeRemote(
   base::flat_set<std::string_view> stop_sequences(kStopSequences.begin(),
                                                   kStopSequences.end());
   api_ = std::make_unique<RemoteCompletionClient>(
-      model_options.name, stop_sequences, url_loader_factory,
-      credential_manager);
+      model_options.name, std::move(stop_sequences),
+      std::move(url_loader_factory), credential_manager);
 
   max_page_content_length_ = model_options.max_page_content_length;
 }
@@ -222,7 +222,7 @@ void EngineConsumerClaudeRemote::GenerateQuestionSuggestions(
   stop_sequences.push_back("</response>");
 
   api_->QueryPrompt(
-      prompt, stop_sequences,
+      prompt, std::move(stop_sequences),
       base::BindOnce(
           &EngineConsumerClaudeRemote::OnGenerateQuestionSuggestionsResponse,
           weak_ptr_factory_.GetWeakPtr(), std::move(callback)));

components/ai_chat/core/browser/engine/engine_consumer_llama.cc

@@ -330,8 +330,8 @@ EngineConsumerLlamaRemote::EngineConsumerLlamaRemote(
   base::flat_set<std::string_view> stop_sequences(kStopSequences.begin(),
                                                   kStopSequences.end());
   api_ = std::make_unique<RemoteCompletionClient>(
-      model_options.name, stop_sequences, url_loader_factory,
-      credential_manager);
+      model_options.name, std::move(stop_sequences),
+      std::move(url_loader_factory), credential_manager);
 
   max_page_content_length_ = model_options.max_page_content_length;
 
@@ -374,7 +374,7 @@ void EngineConsumerLlamaRemote::GenerateQuestionSuggestions(
   stop_sequences.push_back("</ul>");
   DCHECK(api_);
   api_->QueryPrompt(
-      prompt, stop_sequences,
+      prompt, std::move(stop_sequences),
       base::BindOnce(
           &EngineConsumerLlamaRemote::OnGenerateQuestionSuggestionsResponse,
           weak_ptr_factory_.GetWeakPtr(), std::move(callback)));

components/ai_chat/core/browser/engine/mock_remote_completion_client.h

@@ -22,7 +22,7 @@ class MockRemoteCompletionClient : public RemoteCompletionClient {
   MOCK_METHOD(void,
               QueryPrompt,
               (const std::string&,
-               const std::vector<std::string>&,
+               std::vector<std::string>,
                GenerationCompletedCallback,
                GenerationDataCallback),
               (override));

components/ai_chat/core/browser/engine/remote_completion_client.cc

@@ -120,25 +120,26 @@ GURL GetEndpointUrl(bool premium, const std::string& path) {
 
 RemoteCompletionClient::RemoteCompletionClient(
     const std::string& model_name,
-    const base::flat_set<std::string_view>& stop_sequences,
+    base::flat_set<std::string_view> stop_sequences,
     scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
     AIChatCredentialManager* credential_manager)
     : model_name_(model_name),
-      stop_sequences_(stop_sequences),
-      api_request_helper_(GetNetworkTrafficAnnotationTag(), url_loader_factory),
+      stop_sequences_(std::move(stop_sequences)),
+      api_request_helper_(GetNetworkTrafficAnnotationTag(),
+                          std::move(url_loader_factory)),
       credential_manager_(credential_manager) {}
 
 RemoteCompletionClient::~RemoteCompletionClient() = default;
 
 void RemoteCompletionClient::QueryPrompt(
     const std::string& prompt,
-    const std::vector<std::string>& extra_stop_sequences,
+    std::vector<std::string> extra_stop_sequences,
     GenerationCompletedCallback data_completed_callback,
     GenerationDataCallback
         data_received_callback /* = base::NullCallback() */) {
   auto callback = base::BindOnce(
       &RemoteCompletionClient::OnFetchPremiumCredential,
-      weak_ptr_factory_.GetWeakPtr(), prompt, extra_stop_sequences,
+      weak_ptr_factory_.GetWeakPtr(), prompt, std::move(extra_stop_sequences),
       std::move(data_completed_callback), std::move(data_received_callback));
   credential_manager_->FetchPremiumCredential(std::move(callback));
 }

components/ai_chat/core/browser/engine/remote_completion_client.h

@@ -38,7 +38,7 @@ class RemoteCompletionClient {
 
   RemoteCompletionClient(
       const std::string& model_name,
-      const base::flat_set<std::string_view>& stop_sequences,
+      base::flat_set<std::string_view> stop_sequences,
       scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
       AIChatCredentialManager* credential_manager);
 
@@ -50,7 +50,7 @@ class RemoteCompletionClient {
   // In non-SSE cases, only the data_completed_callback will be triggered.
   virtual void QueryPrompt(
       const std::string& prompt,
-      const std::vector<std::string>& stop_sequences,
+      std::vector<std::string> stop_sequences,
       GenerationCompletedCallback data_completed_callback,
       GenerationDataCallback data_received_callback = base::NullCallback());
   // Clears all in-progress requests

components/brave_ads/browser/ads_service_impl.cc

@@ -1016,7 +1016,7 @@ void AdsServiceImpl::URLRequestCallback(
   mojom_url_response->url = url_loader->GetFinalURL();
   mojom_url_response->status_code = response_code;
   mojom_url_response->body = response_body ? *response_body : "";
-  mojom_url_response->headers = headers;
+  mojom_url_response->headers = std::move(headers);
 
   std::move(callback).Run(std::move(mojom_url_response));
 }

components/brave_news/browser/peeking_card.cc

@@ -64,7 +64,7 @@ base::flat_set<std::string> GetTopStoryUrls(
 
 std::optional<size_t> PickPeekingCardWithMax(
     SubscriptionsSnapshot subscriptions,
-    base::flat_set<std::string> top_story_urls,
+    const base::flat_set<std::string>& top_story_urls,
     const ArticleInfos& articles,
     size_t max_candidates) {
   // Store now, so it's consistent for everything.
@@ -217,11 +217,10 @@ std::optional<size_t> PickPeekingCardWithMax(
 
 std::optional<size_t> PickPeekingCard(
     SubscriptionsSnapshot subscriptions,
-    base::flat_set<std::string> top_story_urls,
+    const base::flat_set<std::string>& top_story_urls,
     const ArticleInfos& articles) {
-  return PickPeekingCardWithMax(std::move(subscriptions),
-                                std::move(top_story_urls), articles,
-                                kMaxPeekingCardCandidates);
+  return PickPeekingCardWithMax(std::move(subscriptions), top_story_urls,
+                                articles, kMaxPeekingCardCandidates);
 }
 
 }  // namespace brave_news