internal/lsp: fix merge conflict and race condition

Race condition: I deleted the code that acquired the mutex when checking
if a file's imports have changed.

Merge conflict: I submitted a change without rebasing and re-running TryBots.

Change-Id: Iae351f2fff893cfd94db79d9f79578d9827a8c21
Reviewed-on: https://go-review.googlesource.com/c/tools/+/197297
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>

internal/lsp/cache/load.go

@@ -136,6 +136,9 @@ func (v *view) checkMetadata(ctx context.Context, f *goFile, fh source.FileHandl
 // determine if they have changed.
 // It assumes that the caller holds the lock on the f.mu lock.
 func (v *view) shouldRunGopackages(ctx context.Context, f *goFile, file *ast.File, metadata []*metadata) bool {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
 	// Check if the package's name has changed, by checking if this is a filename
 	// we already know about, and if so, check if its package name has changed.
 	for _, m := range metadata {

internal/lsp/source/completion_literal.go

@@ -284,7 +284,7 @@ func (c *completer) basicLiteral(T types.Type, typeName string, matchScore float
 		InsertText: nonSnippet,
 		Detail:     T.String(),
 		Score:      matchScore * literalCandidateScore,
-		Kind:       VariableCompletionItem,
+		Kind:       protocol.VariableCompletion,
 		snippet:    snip,
 	})
 }