[spanify] Use safe buffers pt.1 (#26486)

This change touches in a few places where safe buffers usage can be
improved, by making use of `base::span`, and `std::array`.

base/process/process_launcher_posix.cc

@@ -5,6 +5,7 @@
 
 #include "brave/base/process/process_launcher.h"
 
+#include <array>
 #include <optional>
 #include <string>
 #include <vector>
@@ -22,7 +23,7 @@ std::optional<std::string> ProcessLauncher::ReadAppOutput(
     base::CommandLine cmdline,
     base::LaunchOptions options,
     int timeout_sec) {
-  int pipe_fd[2];
+  std::array<int, 2> pipe_fd;
   if (pipe(pipe_fd) < 0) {
     return std::nullopt;
   }

browser/ui/views/brave_ads/color_util.cc

@@ -5,7 +5,11 @@
 
 #include "brave/browser/ui/views/brave_ads/color_util.h"
 
+#include <array>
+
 #include "base/compiler_specific.h"
+#include "base/containers/span_reader.h"
+#include "base/containers/span_writer.h"
 #include "base/strings/string_number_conversions.h"
 
 namespace brave_ads {
@@ -21,18 +25,17 @@ bool RgbStringToSkColor(std::string_view rgb, SkColor* color) {
     return false;
   }
 
-  uint32_t components[kColorComponentsCount];
-  for (size_t i = 0; i < kColorComponentsCount; ++i) {
-    const size_t beg = kColorComponentLen * i;
-    uint32_t component = 0;
-    if (!base::HexStringToUInt(rgb.substr(beg, kColorComponentLen),
-                               &component)) {
+  std::array<uint32_t, kColorComponentsCount> hex;
+  base::SpanReader<const char> reader(rgb);
+  base::SpanWriter<uint32_t> writer(hex);
+  while (auto component = reader.Read<kColorComponentLen>()) {
+    uint32_t value;
+    if (!base::HexStringToUInt(base::as_string_view(*component), &value)) {
       return false;
     }
-    UNSAFE_TODO(components[i] = component);
+    writer.Write(value);
   }
-
-  *color = SkColorSetRGB(components[0], components[1], components[2]);
+  *color = SkColorSetRGB(hex[0], hex[1], hex[2]);
   return true;
 }
 

browser/ui/views/brave_help_bubble/brave_help_bubble_delegate_view.cc

@@ -5,6 +5,7 @@
 
 #include "brave/browser/ui/views/brave_help_bubble/brave_help_bubble_delegate_view.h"
 
+#include <array>
 #include <utility>
 
 #include "base/strings/utf_string_conversions.h"
@@ -101,7 +102,7 @@ class BorderWithArrow : public views::BubbleBorder {
                              BubbleArrowPart part) {
     constexpr size_t kNumPoints = 4;
     gfx::RectF bounds_f(bounds);
-    SkPoint points[kNumPoints];
+    std::array<SkPoint, kNumPoints> points;
     switch (GetBubbleArrowSide(arrow)) {
       case views::BubbleArrowSide::kRight:
         points[0] = {bounds_f.x(), bounds_f.y()};
@@ -137,7 +138,8 @@ class BorderWithArrow : public views::BubbleBorder {
         break;
     }
 
-    return SkPath::Polygon(points, kNumPoints, part == BubbleArrowPart::kFill);
+    return SkPath::Polygon(points.data(), kNumPoints,
+                           part == BubbleArrowPart::kFill);
   }
 };
 }  // namespace

browser/ui/webui/brave_webui_source.cc

@@ -3,18 +3,13 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#ifdef UNSAFE_BUFFERS_BUILD
-// TODO(https://github.com/brave/brave-browser/issues/41661): Remove this and
-// convert code to safer constructs.
-#pragma allow_unsafe_buffers
-#endif
-
 #include "brave/browser/ui/webui/brave_webui_source.h"
 
 #include <string_view>
 #include <vector>
 
 #include "base/containers/flat_map.h"
+#include "base/containers/span.h"
 #include "base/strings/utf_string_conversions.h"
 #include "brave/components/constants/url_constants.h"
 #include "brave/components/tor/buildflags/buildflags.h"
@@ -61,7 +56,7 @@ void CustomizeWebUIHTMLSource(content::WebUI* web_ui,
 content::WebUIDataSource* CreateWebUIDataSource(
     content::WebUI* web_ui,
     const std::string& name,
-    const webui::ResourcePath* resource_map,
+    base::span<const webui::ResourcePath> resource_map,
     size_t resource_map_size,
     int html_resource_id,
     bool disable_trusted_types_csp) {
@@ -87,8 +82,8 @@ content::WebUIDataSource* CreateWebUIDataSource(
   source->UseStringsJs();
   source->SetDefaultResource(html_resource_id);
   // Add generated resource paths
-  for (size_t i = 0; i < resource_map_size; ++i) {
-    source->AddResourcePath(resource_map[i].path, resource_map[i].id);
+  for (const auto& resource : resource_map) {
+    source->AddResourcePath(resource.path, resource.id);
   }
   CustomizeWebUIHTMLSource(web_ui, name, source);
   return source;
@@ -99,7 +94,7 @@ content::WebUIDataSource* CreateWebUIDataSource(
 content::WebUIDataSource* CreateAndAddWebUIDataSource(
     content::WebUI* web_ui,
     const std::string& name,
-    const webui::ResourcePath* resource_map,
+    base::span<const webui::ResourcePath> resource_map,
     size_t resource_map_size,
     int html_resource_id,
     bool disable_trusted_types_csp) {

browser/ui/webui/brave_webui_source.h

@@ -8,6 +8,7 @@
 
 #include <string>
 
+#include "base/containers/span.h"
 #include "build/build_config.h"
 
 namespace content {
@@ -24,7 +25,7 @@ struct ResourcePath;
 content::WebUIDataSource* CreateAndAddWebUIDataSource(
     content::WebUI* web_ui,
     const std::string& name,
-    const webui::ResourcePath* resource_map,
+    base::span<const webui::ResourcePath> resource_map,
     size_t resouece_map_size,
     int html_resource_id,
     bool disable_trusted_types_csp = false);