//ui/accessibility: use base::EmptyString() where appropriate

Other empty containers are marked as const to ensure that they stay
empty.

Change-Id: I6771a853cf3cde47fcdcff1e3af7862234f04683
Reviewed-on: https://chromium-review.googlesource.com/c/1298399Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602520}

ui/accessibility/ax_node_data.cc

@@ -311,9 +311,8 @@ bool AXNodeData::HasStringAttribute(
 
 const std::string& AXNodeData::GetStringAttribute(
     ax::mojom::StringAttribute attribute) const {
-  static base::NoDestructor<std::string> empty_string;
   auto iter = FindInVectorOfPairs(attribute, string_attributes);
-  return iter != string_attributes.end() ? iter->second : *empty_string;
+  return iter != string_attributes.end() ? iter->second : base::EmptyString();
 }
 
 bool AXNodeData::GetStringAttribute(ax::mojom::StringAttribute attribute,
@@ -352,7 +351,7 @@ bool AXNodeData::HasIntListAttribute(
 
 const std::vector<int32_t>& AXNodeData::GetIntListAttribute(
     ax::mojom::IntListAttribute attribute) const {
-  static base::NoDestructor<std::vector<int32_t>> empty_vector;
+  static const base::NoDestructor<std::vector<int32_t>> empty_vector;
   auto iter = FindInVectorOfPairs(attribute, intlist_attributes);
   if (iter != intlist_attributes.end())
     return iter->second;
@@ -378,7 +377,7 @@ bool AXNodeData::HasStringListAttribute(
 
 const std::vector<std::string>& AXNodeData::GetStringListAttribute(
     ax::mojom::StringListAttribute attribute) const {
-  static base::NoDestructor<std::vector<std::string>> empty_vector;
+  static const base::NoDestructor<std::vector<std::string>> empty_vector;
   auto iter = FindInVectorOfPairs(attribute, stringlist_attributes);
   if (iter != stringlist_attributes.end())
     return iter->second;

ui/accessibility/platform/ax_platform_node_base.cc

@@ -28,7 +28,7 @@ void AXPlatformNodeBase::Init(AXPlatformNodeDelegate* delegate) {
 }
 
 const AXNodeData& AXPlatformNodeBase::GetData() const {
-  static base::NoDestructor<AXNodeData> empty_data;
+  static const base::NoDestructor<AXNodeData> empty_data;
   if (delegate_)
     return delegate_->GetData();
   return *empty_data;
@@ -190,9 +190,8 @@ bool AXPlatformNodeBase::HasStringAttribute(
 
 const std::string& AXPlatformNodeBase::GetStringAttribute(
     ax::mojom::StringAttribute attribute) const {
-  static base::NoDestructor<std::string> empty_data;
   if (!delegate_)
-    return *empty_data;
+    return base::EmptyString();
   return GetData().GetStringAttribute(attribute);
 }
 
@@ -228,7 +227,7 @@ bool AXPlatformNodeBase::HasIntListAttribute(
 
 const std::vector<int32_t>& AXPlatformNodeBase::GetIntListAttribute(
     ax::mojom::IntListAttribute attribute) const {
-  static base::NoDestructor<std::vector<int32_t>> empty_data;
+  static const base::NoDestructor<std::vector<int32_t>> empty_data;
   if (!delegate_)
     return *empty_data;
   return GetData().GetIntListAttribute(attribute);