Revert of cc: Add mailbox support to ResourceProvider write locks.

cc/tiles/tile_manager_unittest.cc

Index: cc/tiles/tile_manager_unittest.cc
diff --git a/cc/tiles/tile_manager_unittest.cc b/cc/tiles/tile_manager_unittest.cc
index 0492417226851639da655baf119c61d0c3e6c04b..f910c7a9fda68a600054fe5e24a0a5b2878f9e20 100644
--- a/cc/tiles/tile_manager_unittest.cc
+++ b/cc/tiles/tile_manager_unittest.cc
@@ -1811,6 +1811,15 @@
   uint64_t expected_resource_id_;
 };
 
+class VerifyResourceContentIdTileTaskManager : public FakeTileTaskManagerImpl {
+ public:
+  explicit VerifyResourceContentIdTileTaskManager(uint64_t expected_resource_id)
+      : FakeTileTaskManagerImpl(base::WrapUnique<RasterBufferProvider>(
+            new VerifyResourceContentIdRasterBufferProvider(
+                expected_resource_id))) {}
+  ~VerifyResourceContentIdTileTaskManager() override {}
+};
+
 // Runs a test to ensure that partial raster is either enabled or disabled,
 // depending on |partial_raster_enabled|'s value. Takes ownership of host_impl
 // so that cleanup order can be controlled.
@@ -1824,13 +1833,9 @@
 
   // Create a VerifyResourceContentIdTileTaskManager to ensure that the
   // raster task we see is created with |kExpectedId|.
-  FakeTileTaskManagerImpl tile_task_manager;
-  host_impl->tile_manager()->SetTileTaskManagerForTesting(&tile_task_manager);
-
-  VerifyResourceContentIdRasterBufferProvider raster_buffer_provider(
-      kExpectedId);
-  host_impl->tile_manager()->SetRasterBufferProviderForTesting(
-      &raster_buffer_provider);
+  VerifyResourceContentIdTileTaskManager verifying_task_manager(kExpectedId);
+  host_impl->tile_manager()->SetTileTaskManagerForTesting(
+      &verifying_task_manager);
 
   // Ensure there's a resource with our |kInvalidatedId| in the resource pool.
   host_impl->resource_pool()->ReleaseResource(