[Extensions] Convert vector of Alias(es) to base::span in API.

Bug: 847237
Change-Id: Ia95ec62d92a31bc5c71d53c355b6cb577acb4350
Reviewed-on: https://chromium-review.googlesource.com/1244099Reviewed-by: Trent Apted <tapted@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: David Bertoni <dbertoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594794}

chrome/common/apps/platform_apps/chrome_apps_api_provider.cc

@@ -54,7 +54,8 @@ base::StringPiece ChromeAppsAPIProvider::GetAPISchema(const std::string& name) {
 void ChromeAppsAPIProvider::RegisterPermissions(
     extensions::PermissionsInfo* permissions_info) {
   permissions_info->RegisterPermissions(
-      chrome_apps_api_permissions::GetPermissionInfos(), {});
+      chrome_apps_api_permissions::GetPermissionInfos(),
+      base::span<const extensions::Alias>());
 }
 
 void ChromeAppsAPIProvider::RegisterManifestHandlers() {

chrome/common/extensions/permissions/chrome_api_permissions.cc

@@ -235,10 +235,12 @@ base::span<const APIPermissionInfo::InitInfo> GetPermissionInfos() {
   return base::make_span(permissions_to_register);
 }
 
-std::vector<Alias> GetPermissionAliases() {
+base::span<const Alias> GetPermissionAliases() {
   // In alias constructor, first value is the alias name; second value is the
   // real name. See also alias.h.
-  return {Alias("windows", "tabs")};
+  static constexpr Alias aliases[] = {Alias("windows", "tabs")};
+
+  return base::make_span(aliases);
 }
 
 }  // namespace chrome_api_permissions

chrome/common/extensions/permissions/chrome_api_permissions.h

@@ -5,8 +5,7 @@
 #ifndef CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_API_PERMISSIONS_H_
 #define CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_API_PERMISSIONS_H_
 
-#include <vector>
-
+#include "base/containers/span.h"
 #include "extensions/common/alias.h"
 #include "extensions/common/permissions/api_permission.h"
 
@@ -18,7 +17,7 @@ namespace chrome_api_permissions {
 base::span<const APIPermissionInfo::InitInfo> GetPermissionInfos();
 
 // Returns the list of aliases for chrome-layer extension APIPermissions.
-std::vector<Alias> GetPermissionAliases();
+base::span<const Alias> GetPermissionAliases();
 
 }  // namespace chrome_api_permissions
 }  // namespace extensions

extensions/common/alias.h

@@ -5,8 +5,6 @@
 #ifndef EXTENSIONS_COMMON_ALIAS_H_
 #define EXTENSIONS_COMMON_ALIAS_H_
 
-#include <string>
-
 namespace extensions {
 
 // Information about an alias.
@@ -15,24 +13,18 @@ namespace extensions {
 // features when they get renamed. Old feature name can be defined as an alias
 // for the new feature name - this would ensure that the extensions using the
 // old feature name don't break.
-class Alias {
- public:
-  // |name|: The alias name.
-  // |real_name|: The real name behind alias.
-  Alias(const char* const name, const char* const real_name)
-      : name_(name), real_name_(real_name) {}
-  ~Alias() {}
-
-  const std::string& name() const { return name_; }
-
-  const std::string& real_name() const { return real_name_; }
+struct Alias {
+  // This struct is meant to contain pointers to character string constants,
+  // so the lifetime of the pointer parameters should exceed that of the Alias
+  // instance.
+  constexpr Alias(const char* name, const char* real_name)
+      : name(name), real_name(real_name) {}
 
- private:
   // The alias name.
-  std::string name_;
+  const char* name;
 
   // The real name behind the alias.
-  std::string real_name_;
+  const char* real_name;
 };
 
 }  // namespace extensions

extensions/common/permissions/extensions_api_permissions.cc

@@ -130,13 +130,16 @@ base::span<const APIPermissionInfo::InitInfo> GetPermissionInfos() {
   return base::make_span(permissions_to_register);
 }
 
-std::vector<Alias> GetPermissionAliases() {
+base::span<const Alias> GetPermissionAliases() {
   // In alias constructor, first value is the alias name; second value is the
   // real name. See also alias.h.
-  return {Alias("alwaysOnTopWindows", "app.window.alwaysOnTop"),
-          Alias("fullscreen", "app.window.fullscreen"),
-          Alias("overrideEscFullscreen", "app.window.fullscreen.overrideEsc"),
-          Alias("unlimited_storage", "unlimitedStorage")};
+  static constexpr Alias aliases[] = {
+      Alias("alwaysOnTopWindows", "app.window.alwaysOnTop"),
+      Alias("fullscreen", "app.window.fullscreen"),
+      Alias("overrideEscFullscreen", "app.window.fullscreen.overrideEsc"),
+      Alias("unlimited_storage", "unlimitedStorage")};
+
+  return base::make_span(aliases);
 }
 
 }  // namespace api_permissions

extensions/common/permissions/extensions_api_permissions.h

@@ -5,8 +5,6 @@
 #ifndef EXTENSIONS_COMMON_PERMISSIONS_EXTENSIONS_API_PERMISSIONS_H_
 #define EXTENSIONS_COMMON_PERMISSIONS_EXTENSIONS_API_PERMISSIONS_H_
 
-#include <vector>
-
 #include "base/containers/span.h"
 #include "extensions/common/alias.h"
 #include "extensions/common/permissions/api_permission.h"
@@ -15,7 +13,7 @@ namespace extensions {
 namespace api_permissions {
 
 base::span<const APIPermissionInfo::InitInfo> GetPermissionInfos();
-std::vector<Alias> GetPermissionAliases();
+base::span<const Alias> GetPermissionAliases();
 
 }  // namespace api_permissions
 }  // namespace extensions

extensions/common/permissions/permissions_info.cc

@@ -23,7 +23,7 @@ PermissionsInfo* PermissionsInfo::GetInstance() {
 
 void PermissionsInfo::RegisterPermissions(
     base::span<const APIPermissionInfo::InitInfo> infos,
-    const std::vector<Alias>& aliases) {
+    base::span<const Alias> aliases) {
   for (const auto& info : infos)
     RegisterPermission(base::WrapUnique(new APIPermissionInfo((info))));
 
@@ -75,9 +75,9 @@ PermissionsInfo::~PermissionsInfo() {
 }
 
 void PermissionsInfo::RegisterAlias(const Alias& alias) {
-  DCHECK(base::ContainsKey(name_map_, alias.real_name()));
-  DCHECK(!base::ContainsKey(name_map_, alias.name()));
-  name_map_[alias.name()] = name_map_[alias.real_name()];
+  DCHECK(base::ContainsKey(name_map_, alias.real_name));
+  DCHECK(!base::ContainsKey(name_map_, alias.name));
+  name_map_[alias.name] = name_map_[alias.real_name];
 }
 
 void PermissionsInfo::RegisterPermission(

extensions/common/permissions/permissions_info.h

@@ -23,7 +23,7 @@
 
 namespace extensions {
 
-class Alias;
+struct Alias;
 
 // A global object that holds the extension permission instances and provides
 // methods for accessing them.
@@ -33,9 +33,8 @@ class PermissionsInfo {
 
   // Registers the permissions specified by |infos| along with the
   // |aliases|.
-  // TODO(devlin): Convert |aliases| to be a base::span.
   void RegisterPermissions(base::span<const APIPermissionInfo::InitInfo> infos,
-                           const std::vector<Alias>& aliases);
+                           base::span<const Alias> aliases);
 
   // Returns the permission with the given |id|, and NULL if it doesn't exist.
   const APIPermissionInfo* GetByID(APIPermission::ID id) const;