[tools] Consider today for gerrit-stats and snippets

When you do not specify the --before and --after flags, the tools should consider the window of [N-days-ago .. now].

'Before' is not inclusive, so push it forward 24 hours to include today.

Change-Id: I4c04bcb3c318a83091aeebacddd67e47170508ae
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/134500
Kokoro: Kokoro <noreply+kokoro@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

tools/src/cmd/gerrit-stats/main.go

@@ -80,7 +80,7 @@ func run() error {
 			return fmt.Errorf("Couldn't parse before date: %w", err)
 		}
 	} else {
-		before = time.Now()
+		before = time.Now().Add(time.Hour * 24)
 	}
 	if *afterFlag != "" {
 		after, err = time.Parse(yyyymmdd, *afterFlag)

tools/src/cmd/snippets/main.go

@@ -77,7 +77,7 @@ func run() error {
 			return fmt.Errorf("Couldn't parse before date: %w", err)
 		}
 	} else {
-		before = time.Now()
+		before = time.Now().Add(time.Hour * 24)
 	}
 	if *afterFlag != "" {
 		after, err = time.Parse(yyyymmdd, *afterFlag)
@@ -113,8 +113,8 @@ func run() error {
 	for _, project := range []string{"tint", "dawn"} {
 		if changes := changesByProject[project]; len(changes) > 0 {
 			fmt.Println("##", strings.Title(project))
-			for _, change := range changes {
-				fmt.Println(change)
+			for i := len(changes) - 1; i >= 0; i-- {
+				fmt.Println(changes[i])
 			}
 			fmt.Println()
 		}