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

cc/test/fake_tile_task_manager.cc

Index: cc/test/fake_tile_task_manager.cc
diff --git a/cc/test/fake_tile_task_manager.cc b/cc/test/fake_tile_task_manager.cc
index 044de23ea865a26406a7486ac376f78b482ef0f9..cc7019897def8af11f5bb393f5a347bf07848368 100644
--- a/cc/test/fake_tile_task_manager.cc
+++ b/cc/test/fake_tile_task_manager.cc
@@ -8,7 +8,13 @@
 
 namespace cc {
 
-FakeTileTaskManagerImpl::FakeTileTaskManagerImpl() {}
+FakeTileTaskManagerImpl::FakeTileTaskManagerImpl()
+    : raster_buffer_provider_(base::WrapUnique<RasterBufferProvider>(
+          new FakeRasterBufferProviderImpl)) {}
+
+FakeTileTaskManagerImpl::FakeTileTaskManagerImpl(
+    std::unique_ptr<RasterBufferProvider> raster_buffer_provider)
+    : raster_buffer_provider_(std::move(raster_buffer_provider)) {}
 
 FakeTileTaskManagerImpl::~FakeTileTaskManagerImpl() {
   DCHECK_EQ(0u, completed_tasks_.size());
@@ -36,4 +42,8 @@
 
 void FakeTileTaskManagerImpl::Shutdown() {}
 
+RasterBufferProvider* FakeTileTaskManagerImpl::GetRasterBufferProvider() const {
+  return raster_buffer_provider_.get();
+}
+
 }  // namespace cc