[maintenance] migrate deps to libs.versions.toml (#8923)

Fixes: #8921.

---

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<details>
  <summary>Contribution guidelines:</summary><br>

- See
  our [contributor guide](../CONTRIBUTING.md) and
  the [Flutter organization contributor guide]([https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md)
  for general expectations for PRs.
- Larger or significant changes should be discussed in an issue before creating a PR.
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  `dart format`.
- Java and Kotlin contributions should strive to follow Java and Kotlin best
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</details>

Author: pq

build.gradle.kts

@@ -40,10 +40,10 @@ plugins {
   // https://plugins.gradle.org/plugin/org.jetbrains.intellij.platform
   // https://plugins.gradle.org/plugin/org.jetbrains.kotlin.jvm
   id("java") // Java support
-  id("org.jetbrains.intellij.platform") version "2.12.0" // IntelliJ Platform Gradle Plugin
-  id("org.jetbrains.kotlin.jvm") version "2.2.0" // Kotlin support
-  id("org.jetbrains.changelog") version "2.2.0" // Gradle Changelog Plugin
-  id("org.jetbrains.kotlinx.kover") version "0.9.4"
+  alias(libs.plugins.intellij.platform) // IntelliJ Platform Gradle Plugin
+  alias(libs.plugins.kotlin.jvm) // Kotlin support
+  alias(libs.plugins.changelog) // Gradle Changelog Plugin
+  alias(libs.plugins.kover)
   idea // IntelliJ IDEA support
 }
 
@@ -239,13 +239,13 @@ dependencies {
     pluginVerifier()
   }
 
-  compileOnly("org.jetbrains:annotations:24.0.0")
-  testImplementation("org.jetbrains:annotations:24.0.0")
-  compileOnly("com.google.guava:guava:32.0.1-android")
-  compileOnly("com.google.code.gson:gson:2.10.1")
-  testImplementation("com.google.guava:guava:32.0.1-jre")
-  testImplementation("com.google.code.gson:gson:2.10.1")
-  testImplementation("junit:junit:4.13.2")
+  compileOnly(libs.jetbrains.annotations)
+  testImplementation(libs.jetbrains.annotations)
+  compileOnly(libs.guava.android)
+  compileOnly(libs.gson)
+  testImplementation(libs.guava.jre)
+  testImplementation(libs.gson)
+  testImplementation(libs.junit)
   implementation(
     fileTree(
       mapOf(
@@ -256,12 +256,12 @@ dependencies {
   )
 
   // UI Test dependencies
-  integrationImplementation("org.kodein.di:kodein-di-jvm:7.26.1")
-  integrationImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0")
+  integrationImplementation(libs.kodein.di)
+  integrationImplementation(libs.kotlinx.coroutines)
 
   // JUnit 5 is required for UI tests
-  integrationImplementation("org.junit.jupiter:junit-jupiter:5.11.4")
-  integrationRuntimeOnly("org.junit.platform:junit-platform-launcher")
+  integrationImplementation(libs.junit.jupiter)
+  integrationRuntimeOnly(libs.junit.platform.launcher)
 }
 
 intellijPlatform {

gradle/libs.versions.toml

@@ -0,0 +1,35 @@
+# Copyright 2026 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+[versions]
+jetbrains-annotations = "24.0.0"
+guava-android = "32.0.1-android"
+guava-jre = "32.0.1-jre"
+gson = "2.10.1"
+junit = "4.13.2"
+kodein-di = "7.26.1"
+kotlinx-coroutines = "1.9.0"
+junit-jupiter = "5.11.4"
+junit-platform = "1.11.4"
+intellij-platform-plugin = "2.12.0"
+kotlin = "2.2.0"
+changelog = "2.2.0"
+kover = "0.9.4"
+
+[libraries]
+jetbrains-annotations = { group = "org.jetbrains", name = "annotations", version.ref = "jetbrains-annotations" }
+guava-android = { group = "com.google.guava", name = "guava", version.ref = "guava-android" }
+guava-jre = { group = "com.google.guava", name = "guava", version.ref = "guava-jre" }
+gson = { group = "com.google.code.gson", name = "gson", version.ref = "gson" }
+junit = { group = "junit", name = "junit", version.ref = "junit" }
+kodein-di = { group = "org.kodein.di", name = "kodein-di-jvm", version.ref = "kodein-di" }
+kotlinx-coroutines = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-core", version.ref = "kotlinx-coroutines" }
+junit-jupiter = { group = "org.junit.jupiter", name = "junit-jupiter", version.ref = "junit-jupiter" }
+junit-platform-launcher = { group = "org.junit.platform", name = "junit-platform-launcher", version.ref = "junit-platform" }
+
+[plugins]
+intellij-platform = { id = "org.jetbrains.intellij.platform", version.ref = "intellij-platform-plugin" }
+kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
+changelog = { id = "org.jetbrains.changelog", version.ref = "changelog" }
+kover = { id = "org.jetbrains.kotlinx.kover", version.ref = "kover" }