Restore compositor worker thread names.

Some of our tests apparently rely on these threads having
specific names.

BUG=470091

Review URL: https://codereview.chromium.org/1036923002

Cr-Commit-Position: refs/heads/master@{#322303}

cc/test/test_task_graph_runner.cc

@@ -7,7 +7,7 @@
 namespace cc {
 
 TestTaskGraphRunner::TestTaskGraphRunner()
-    : worker_thread_(this, "CompositorWorker") {
+    : worker_thread_(this, "CompositorTileWorker1") {
   worker_thread_.Start();
 }
 

content/browser/compositor/gpu_process_transport_factory.cc

@@ -72,7 +72,7 @@ namespace {
 class RasterThread : public base::SimpleThread {
  public:
   RasterThread(cc::TaskGraphRunner* task_graph_runner)
-      : base::SimpleThread("UICompositorWorker"),
+      : base::SimpleThread("CompositorTileWorker1"),
         task_graph_runner_(task_graph_runner) {}
 
   // Overridden from base::SimpleThread:

content/browser/renderer_host/compositor_impl_android.cc

@@ -143,7 +143,8 @@ class SingleThreadTaskGraphRunner
     : public cc::TaskGraphRunner,
       public base::DelegateSimpleThread::Delegate {
  public:
-  SingleThreadTaskGraphRunner() : worker_thread_(this, "CompositorWorker") {
+  SingleThreadTaskGraphRunner()
+      : worker_thread_(this, "CompositorTileWorker1") {
     worker_thread_.Start();
     worker_thread_.SetThreadPriority(base::kThreadPriority_Background);
   }

content/renderer/render_thread_impl.cc

@@ -668,7 +668,7 @@ void RenderThreadImpl::Init() {
           new CompositorRasterThread(
               compositor_task_graph_runner_.get(),
               base::StringPrintf(
-                  "CompositorWorker%u",
+                  "CompositorTileWorker%u",
                   static_cast<unsigned>(compositor_raster_threads_.size() + 1))
                   .c_str()));
       raster_thread->Start();