Pass initial size and GPU preference via context attributes

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 1226bb4b64d5e759bbd6b7a79c9962e2c3cc194b..a43b39dd21d59a1de6dff1ddc1efd61596b5d7b4 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -452,8 +452,7 @@ scoped_refptr<ContextProviderCommandBuffer> CreateOffscreenContext(
       std::move(gpu_channel_host), stream_id, stream_priority,
       gpu::kNullSurfaceHandle,
       GURL("chrome://gpu/RenderThreadImpl::CreateOffscreenContext"),
-      gl::PreferIntegratedGpu, automatic_flushes, support_locking, limits,
-      attributes, nullptr, type));
+      automatic_flushes, support_locking, limits, attributes, nullptr, type));
 }
 
 }  // namespace
@@ -1906,8 +1905,7 @@ RenderThreadImpl::CreateCompositorOutputSurface(
       new ContextProviderCommandBuffer(
           gpu_channel_host, gpu::GPU_STREAM_DEFAULT,
           gpu::GpuStreamPriority::NORMAL, gpu::kNullSurfaceHandle, url,
-          gl::PreferIntegratedGpu, automatic_flushes, support_locking, limits,
-          attributes, share_context,
+          automatic_flushes, support_locking, limits, attributes, share_context,
           command_buffer_metrics::RENDER_COMPOSITOR_CONTEXT));
 
   if (layout_test_deps_) {