Revert of Re-land: cc: Use worker context for one-copy tile initialization. (patchset #29 id:560001 of https://codereview.chromium.org/1230203007/ )

Reason for revert:
Sorry Dave. I'm reverting as this broke mandoline. To see the breakage build mandoline:all, and run with:
mandoline --oopif-always-create-new-frame-tree http://phuang.github.io/iframe.html .

We do have mandoline tests that run, but they run with the code path  gfx::GLSurfaceTestSupport::InitializeOneOff(), which is why they likely still pass. I'll see about making the tests not run with that config.

Original issue's description:
> Re-land: cc: Use worker context for one-copy tile initialization.
>
> This moves management of staging resources to
> OneCopyTileTaskWorkerPool class. This makes it possible
> to use a worker context to issue and detect when copy
> operations complete.
>
> BUG=490295
> TBR=jamesr@chromium.org, sky@chromium.org
> CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
>
> Committed: https://crrev.com/af0ab609b53c64ce43172be42e20e7ca8beab497
> Cr-Commit-Position: refs/heads/master@{#343947}

TBR=jamesr@chromium.org,kbr@chromium.org,piman@chromium.org,primiano@chromium.org,vmiura@chromium.org,vmpstr@chromium.org,reveman@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=490295

Review URL: https://codereview.chromium.org/1298143003

Cr-Commit-Position: refs/heads/master@{#344042}

3 files changed, 9 insertions, 19 deletions

diff --git a/ui/compositor/test/in_process_context_factory.cc b/ui/compositor/test/in_process_context_factory.cc
index 942947d..13ddd90 100644
--- a/ui/compositor/test/in_process_context_factory.cc
+++ b/ui/compositor/test/in_process_context_factory.cc
@@ -41,11 +41,9 @@ class FakeReflector : public Reflector {
 // GL surface.
 class DirectOutputSurface : public cc::OutputSurface {
  public:
-  DirectOutputSurface(
-      const scoped_refptr<cc::ContextProvider>& context_provider,
-      const scoped_refptr<cc::ContextProvider>& worker_context_provider)
-      : cc::OutputSurface(context_provider, worker_context_provider),
-        weak_ptr_factory_(this) {}
+  explicit DirectOutputSurface(
+      const scoped_refptr<cc::ContextProvider>& context_provider)
+      : cc::OutputSurface(context_provider), weak_ptr_factory_(this) {}
 
   ~DirectOutputSurface() override {}
 
@@ -112,19 +110,16 @@ void InProcessContextFactory::CreateOutputSurface(
       InProcessContextProvider::Create(attribs, &gpu_memory_buffer_manager_,
                                        &image_factory_,
                                        compositor->widget(), "UICompositor");
-  scoped_refptr<InProcessContextProvider> worker_context_provider =
-      InProcessContextProvider::CreateOffscreen(&gpu_memory_buffer_manager_,
-                                                &image_factory_);
 
   scoped_ptr<cc::OutputSurface> real_output_surface;
 
   if (use_test_surface_) {
     bool flipped_output_surface = false;
     real_output_surface = make_scoped_ptr(new cc::PixelTestOutputSurface(
-        context_provider, worker_context_provider, flipped_output_surface));
+        context_provider, flipped_output_surface));
   } else {
-    real_output_surface = make_scoped_ptr(
-        new DirectOutputSurface(context_provider, worker_context_provider));
+    real_output_surface =
+        make_scoped_ptr(new DirectOutputSurface(context_provider));
   }
 
   if (surface_manager_) {
@@ -134,9 +129,9 @@ void InProcessContextFactory::CreateOutputSurface(
             GetSharedBitmapManager(), GetGpuMemoryBufferManager(),
             compositor->GetRendererSettings(), compositor->task_runner()));
     scoped_ptr<cc::SurfaceDisplayOutputSurface> surface_output_surface(
-        new cc::SurfaceDisplayOutputSurface(
-            surface_manager_, compositor->surface_id_allocator(),
-            context_provider, worker_context_provider));
+        new cc::SurfaceDisplayOutputSurface(surface_manager_,
+                                            compositor->surface_id_allocator(),
+                                            context_provider));
     display_client->set_surface_output_surface(surface_output_surface.get());
     surface_output_surface->set_display_client(display_client.get());
 
diff --git a/ui/compositor/test/in_process_context_provider.cc b/ui/compositor/test/in_process_context_provider.cc
index 76cd19d..c5f950f 100644
--- a/ui/compositor/test/in_process_context_provider.cc
+++ b/ui/compositor/test/in_process_context_provider.cc
@@ -122,10 +122,6 @@ bool InProcessContextProvider::BindToCurrentThread() {
   return true;
 }
 
-void InProcessContextProvider::DetachFromThread() {
-  context_thread_checker_.DetachFromThread();
-}
-
 cc::ContextProvider::Capabilities
 InProcessContextProvider::ContextCapabilities() {
   DCHECK(context_thread_checker_.CalledOnValidThread());
diff --git a/ui/compositor/test/in_process_context_provider.h b/ui/compositor/test/in_process_context_provider.h
index 0f5f35f..bc3e494 100644
--- a/ui/compositor/test/in_process_context_provider.h
+++ b/ui/compositor/test/in_process_context_provider.h
@@ -49,7 +49,6 @@ class InProcessContextProvider : public cc::ContextProvider {
 
   // cc::ContextProvider:
   bool BindToCurrentThread() override;
-  void DetachFromThread() override;
   Capabilities ContextCapabilities() override;
   gpu::gles2::GLES2Interface* ContextGL() override;
   gpu::ContextSupport* ContextSupport() override;