refactor: use base::flat_set in WebContents::DidUpdateFaviconUrl() (#46530)

* refactor: add gin::Converter<std::span>::ToV8()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* feat: add ToV8(const base::flat_set<T>&)

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* perf: use a flat_set in WebContents::TitleWasSet()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* refactor: add gin::Converter<std::array>::ToV8()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

---------

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>

shell/browser/api/electron_api_web_contents.cc

@@ -16,6 +16,7 @@
 
 #include "base/base64.h"
 #include "base/containers/fixed_flat_map.h"
+#include "base/containers/flat_set.h"
 #include "base/containers/id_map.h"
 #include "base/files/file_util.h"
 #include "base/json/json_reader.h"
@@ -2119,13 +2120,12 @@ void WebContents::TitleWasSet(content::NavigationEntry* entry) {
 void WebContents::DidUpdateFaviconURL(
     content::RenderFrameHost* render_frame_host,
     const std::vector<blink::mojom::FaviconURLPtr>& urls) {
-  std::set<GURL> unique_urls;
+  base::flat_set<GURL> unique_urls;
+  unique_urls.reserve(std::size(urls));
   for (const auto& iter : urls) {
-    if (iter->icon_type != blink::mojom::FaviconIconType::kFavicon)
+    if (iter->icon_type == blink::mojom::FaviconIconType::kFavicon &&
-      continue;
+        iter->icon_url.is_valid())
-    const GURL& url = iter->icon_url;
+      unique_urls.insert(iter->icon_url);
-    if (url.is_valid())
-      unique_urls.insert(url);
   }
   Emit("page-favicon-updated", unique_urls);
 }

shell/common/gin_converters/base_converter.h

@@ -5,6 +5,7 @@
 #ifndef ELECTRON_SHELL_COMMON_GIN_CONVERTERS_BASE_CONVERTER_H_
 #define ELECTRON_SHELL_COMMON_GIN_CONVERTERS_BASE_CONVERTER_H_
 
+#include "base/containers/flat_set.h"
 #include "base/process/kill.h"
 #include "gin/converter.h"
 #include "shell/common/gin_converters/std_converter.h"
@@ -41,6 +42,14 @@ struct Converter<base::TerminationStatus> {
   }
 };
 
+template <typename T>
+struct Converter<base::flat_set<T>> {
+  static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
+                                   const base::flat_set<T>& set) {
+    return Converter<std::span<T>>::ToV8(isolate, std::span{set});
+  }
+};
+
 }  // namespace gin
 
 #endif  // ELECTRON_SHELL_COMMON_GIN_CONVERTERS_BASE_CONVERTER_H_

shell/common/gin_converters/std_converter.h

@@ -9,6 +9,7 @@
 #include <functional>
 #include <map>
 #include <set>
+#include <span>
 #include <type_traits>
 #include <utility>
 
@@ -28,6 +29,33 @@ v8::Local<v8::Value> ConvertToV8(v8::Isolate* isolate, T&& input) {
       isolate, std::forward<T>(input));
 }
 
+template <typename T>
+struct Converter<std::span<T>> {
+  static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
+                                   const std::span<const T>& span) {
+    int idx = 0;
+    auto context = isolate->GetCurrentContext();
+    auto result = v8::Array::New(isolate, static_cast<int>(span.size()));
+    for (const auto& val : span) {
+      v8::MaybeLocal<v8::Value> maybe = Converter<T>::ToV8(isolate, val);
+      v8::Local<v8::Value> element;
+      if (!maybe.ToLocal(&element))
+        return {};
+      if (!result->Set(context, idx++, element).FromMaybe(false))
+        NOTREACHED() << "CreateDataProperty should always succeed here.";
+    }
+    return result;
+  }
+};
+
+template <typename T, size_t N>
+struct Converter<std::array<T, N>> {
+  static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
+                                   const std::array<T, N>& array) {
+    return Converter<std::span<T>>::ToV8(isolate, std::span{array});
+  }
+};
+
 #if !BUILDFLAG(IS_LINUX)
 template <>
 struct Converter<unsigned long> {  // NOLINT(runtime/int)