Convert PpdCache and PpdProvider to TaskScheduler.

chromeos/printing/ppd_cache_unittest.cc

Index: chromeos/printing/ppd_cache_unittest.cc
diff --git a/chromeos/printing/ppd_cache_unittest.cc b/chromeos/printing/ppd_cache_unittest.cc
index 4aafe9700e03635cc424544705ae297a1ba02c33..dd021f3842f558cc1aaffee80697c8da3e233366 100644
--- a/chromeos/printing/ppd_cache_unittest.cc
+++ b/chromeos/printing/ppd_cache_unittest.cc
@@ -13,6 +13,7 @@
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chromeos/printing/ppd_cache.h"
 #include "net/url_request/test_url_request_interceptor.h"
@@ -27,7 +28,10 @@ namespace {
 // the test.
 class PpdCacheTest : public ::testing::Test {
  public:
-  PpdCacheTest() : loop_(base::MessageLoop::TYPE_IO) {}
+  PpdCacheTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::IO) {}
+
   void SetUp() override {
     ASSERT_TRUE(ppd_cache_temp_dir_.CreateUniqueTempDir());
   }
@@ -37,8 +41,7 @@ class PpdCacheTest : public ::testing::Test {
   // a (nonexistant) subdirectory of temp_dir_ to the cache to exercise
   // the lazy-creation-of-the-cache-directory code.
   scoped_refptr<PpdCache> CreateTestCache() {
-    return PpdCache::Create(ppd_cache_temp_dir_.GetPath().Append("Cache"),
-                            loop_.task_runner().get());
+    return PpdCache::Create(ppd_cache_temp_dir_.GetPath().Append("Cache"));
   }
 
   void CaptureFindResult(const PpdCache::FindResult& result) {
@@ -49,6 +52,9 @@ class PpdCacheTest : public ::testing::Test {
   void CaptureStoreResult() { ++captured_store_results_; }
 
  protected:
+  // Environment for task schedulers.
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
+
   // Number of find results we've captured.
   int captured_find_results_ = 0;
 
@@ -61,7 +67,6 @@ class PpdCacheTest : public ::testing::Test {
   // Overrider for DIR_CHROMEOS_PPD_CACHE that points it at a temporary
   // directory for the life of the test.
   base::ScopedTempDir ppd_cache_temp_dir_;
-  base::MessageLoop loop_;
 };
 
 
@@ -70,7 +75,7 @@ TEST_F(PpdCacheTest, SimpleMiss) {
   auto cache = CreateTestCache();
   cache->Find("foo", base::Bind(&PpdCacheTest::CaptureFindResult,
                                 base::Unretained(this)));
-  base::RunLoop().RunUntilIdle();
+  scoped_task_environment_.RunUntilIdle();
   EXPECT_EQ(captured_find_results_, 1);
   EXPECT_FALSE(find_result_.success);
 }
@@ -83,19 +88,19 @@ TEST_F(PpdCacheTest, MissThenHit) {
 
   cache->Find(kTestKey, base::Bind(&PpdCacheTest::CaptureFindResult,
                                    base::Unretained(this)));
-  base::RunLoop().RunUntilIdle();
+  scoped_task_environment_.RunUntilIdle();
   EXPECT_EQ(captured_find_results_, 1);
   EXPECT_FALSE(find_result_.success);
 
   cache->Store(
       kTestKey, kTestContents,
       base::Bind(&PpdCacheTest::CaptureStoreResult, base::Unretained(this)));
-  base::RunLoop().RunUntilIdle();
+  scoped_task_environment_.RunUntilIdle();
   EXPECT_EQ(captured_store_results_, 1);
 
   cache->Find(kTestKey, base::Bind(&PpdCacheTest::CaptureFindResult,
                                    base::Unretained(this)));
-  base::RunLoop().RunUntilIdle();
+  scoped_task_environment_.RunUntilIdle();
   EXPECT_EQ(captured_find_results_, 2);
   EXPECT_TRUE(find_result_.success);
   EXPECT_EQ(find_result_.contents, kTestContents);
@@ -103,7 +108,7 @@ TEST_F(PpdCacheTest, MissThenHit) {
 
   cache->Find(kTestKey2, base::Bind(&PpdCacheTest::CaptureFindResult,
                                     base::Unretained(this)));
-  base::RunLoop().RunUntilIdle();
+  scoped_task_environment_.RunUntilIdle();
   EXPECT_EQ(captured_find_results_, 3);
   EXPECT_FALSE(find_result_.success);
 }