Use the budget to control whether overrides are suggested

I believe that this is the right thing to do from a UX perspective, but
this change could potentially cause flakiness in tests. There's support
in the LSP path for setting a bigger budget, but not for legacy based
tests (at least not yet).

Change-Id: I76353fd3e4cb4cf8fb7a55c27a3353415143dc06
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/360740
Reviewed-by: Keerti Parthasarathy <keertip@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/services/completion/dart/completion_manager.dart

@@ -159,7 +159,7 @@ class DartCompletionManager {
     if (selection == null) {
       throw AbortCompletion();
     }
-    var state = CompletionState(request, selection);
+    var state = CompletionState(request, selection, budget);
     var pass = InScopeCompletionPass(
       state: state,
       collector: collector,

pkg/analysis_server/lib/src/services/completion/dart/completion_state.dart

@@ -14,35 +14,41 @@ class CompletionState {
   /// The completion request being processed.
   final DartCompletionRequest request;
 
-  /// The selection at the time completion was requested. The selection is
-  /// required to have a length of zero.
+  /// The selection at the time completion was requested.
+  ///
+  /// The selection is required to have a length of zero.
   final Selection selection;
 
+  /// The budget controlling how much time can be spent computing completion
+  /// suggestions.
+  final CompletionBudget budget;
+
   /// Initialize a newly created completion state.
-  CompletionState(this.request, this.selection) : assert(selection.length == 0);
+  CompletionState(this.request, this.selection, this.budget)
+      : assert(selection.length == 0);
 
-  /// Returns the type of value required by the context in which completion was
+  /// The type of value required by the context in which completion was
   /// requested.
   DartType? get contextType => request.contextType;
 
-  /// Return the [ClassMember] that encloses the completion location, or `null`
-  /// if the completion location isn't in a class member.
+  /// The [ClassMember] that encloses the completion location, or `null` if the
+  /// completion location isn't in a class member.
   ClassMember? get enclosingMember {
     return selection.coveringNode.thisOrAncestorOfType<ClassMember>();
   }
 
-  /// Return `true` if the completion location is inside an instance member, and
-  /// hence there is a binding for `this`.
+  /// Whether the completion location is inside an instance member, and hence
+  /// whether there is a binding for `this`.
   bool get inInstanceScope {
     var member = enclosingMember;
     return member != null && !member.isStatic;
   }
 
-  /// Returns the element of the library containing the completion location.
+  /// The element of the library containing the completion location.
   LibraryElement get libraryElement => request.libraryElement;
 
-  /// Return the type of `this` at the completion location, or `null`
-  /// if the completion location doesn't allow `this` to be used.
+  /// The type of `this` at the completion location, or `null` if the completion
+  /// location doesn't allow `this` to be used.
   DartType? get thisType {
     AstNode? node = selection.coveringNode;
     while (node != null) {
@@ -70,16 +76,16 @@ class CompletionState {
     return null;
   }
 
-  /// Return `true` if the given `feature` is enabled in the library containing
-  /// the selection.
+  /// Whether the given `feature` is enabled in the library containing the
+  /// selection.
   bool isFeatureEnabled(Feature feature) {
     return libraryElement.featureSet.isEnabled(feature);
   }
 }
 
 // TODO(brianwilkerson): Move to 'package:analysis_server/src/utilities/extensions/ast.dart'
 extension on ClassMember {
-  /// Return `true` if this member is a static member.
+  /// Whether this member is a static member.
   bool get isStatic {
     var self = this;
     if (self is MethodDeclaration) {

pkg/analysis_server/lib/src/services/completion/dart/in_scope_completion_pass.dart

@@ -3468,8 +3468,10 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
     required InterfaceElement? element,
     bool skipAt = false,
   }) {
-    // TODO(brianwilkerson): Check whether there's sufficient remaining time
-    //  before computing suggestions for overrides.
+    if (state.budget.isEmpty) {
+      // Don't suggest overrides if the time budget has already been spent.
+      return;
+    }
     if (suggestOverrides && element != null) {
       overrideHelper.computeOverridesFor(
         interfaceElement: element,