Revert of cc: Use worker context for one-copy tile initialization.

content/browser/compositor/gpu_process_transport_factory.cc

Index: content/browser/compositor/gpu_process_transport_factory.cc
diff --git a/content/browser/compositor/gpu_process_transport_factory.cc b/content/browser/compositor/gpu_process_transport_factory.cc
index f03eb9e526224b2b266a847259ad6e471a7dbe26..fcb0a3e8abbb6ad1aefafb3486866c28e8c03371 100644
--- a/content/browser/compositor/gpu_process_transport_factory.cc
+++ b/content/browser/compositor/gpu_process_transport_factory.cc
@@ -237,13 +237,6 @@
 
   scoped_refptr<ContextProviderCommandBuffer> context_provider;
   if (create_gpu_output_surface) {
-    // Try to reuse existing worker context provider.
-    if (shared_worker_context_provider_) {
-      base::AutoLock lock(*shared_worker_context_provider_->GetLock());
-      if (shared_worker_context_provider_->ContextGL()
-              ->GetGraphicsResetStatusKHR() != GL_NO_ERROR)
-        shared_worker_context_provider_ = nullptr;
-    }
     scoped_refptr<GpuChannelHost> gpu_channel_host =
         BrowserGpuChannelHostFactory::instance()->GetGpuChannel();
     if (gpu_channel_host.get()) {
@@ -253,24 +246,12 @@
           BROWSER_COMPOSITOR_ONSCREEN_CONTEXT);
       if (context_provider && !context_provider->BindToCurrentThread())
         context_provider = nullptr;
-      if (!shared_worker_context_provider_) {
-        shared_worker_context_provider_ = ContextProviderCommandBuffer::Create(
-            GpuProcessTransportFactory::CreateContextCommon(gpu_channel_host,
-                                                            0),
-            BROWSER_WORKER_CONTEXT);
-        if (shared_worker_context_provider_ &&
-            !shared_worker_context_provider_->BindToCurrentThread())
-          shared_worker_context_provider_ = nullptr;
-      }
     }
 
-    bool created_gpu_browser_compositor =
-        !!context_provider && !!shared_worker_context_provider_;
-
     UMA_HISTOGRAM_BOOLEAN("Aura.CreatedGpuBrowserCompositor",
-                          created_gpu_browser_compositor);
-
-    if (!created_gpu_browser_compositor) {
+                          !!context_provider.get());
+
+    if (!context_provider) {
       // Try again.
       CauseForGpuLaunch cause =
           CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE;
@@ -293,8 +274,7 @@
         context_provider->ContextCapabilities();
     if (!data->surface_id) {
       surface = make_scoped_ptr(new OffscreenBrowserCompositorOutputSurface(
-          context_provider, shared_worker_context_provider_,
-          compositor->vsync_manager(),
+          context_provider, compositor->vsync_manager(),
           scoped_ptr<BrowserCompositorOverlayCandidateValidator>()));
     } else if (capabilities.gpu.surfaceless) {
       GLenum target = GL_TEXTURE_2D;
@@ -305,15 +285,13 @@
 #endif
       surface =
           make_scoped_ptr(new GpuSurfacelessBrowserCompositorOutputSurface(
-              context_provider, shared_worker_context_provider_,
-              data->surface_id, compositor->vsync_manager(),
+              context_provider, data->surface_id, compositor->vsync_manager(),
               CreateOverlayCandidateValidator(compositor->widget()), target,
               format, BrowserGpuMemoryBufferManager::current()));
     } else {
       if (!surface) {
         surface = make_scoped_ptr(new GpuBrowserCompositorOutputSurface(
-            context_provider, shared_worker_context_provider_,
-            compositor->vsync_manager(),
+            context_provider, compositor->vsync_manager(),
             CreateOverlayCandidateValidator(compositor->widget())));
       }
     }
@@ -344,8 +322,7 @@
 
   scoped_ptr<cc::SurfaceDisplayOutputSurface> output_surface(
       new cc::SurfaceDisplayOutputSurface(
-          manager, compositor->surface_id_allocator(), context_provider,
-          shared_worker_context_provider_));
+          manager, compositor->surface_id_allocator(), context_provider));
   display_client->set_surface_output_surface(output_surface.get());
   output_surface->set_display_client(display_client.get());
   display_client->display()->Resize(compositor->size());