cc: Remove the software compositing bool from PrepareTextureMailbox

ui/compositor/layer.h

Index: ui/compositor/layer.h
diff --git a/ui/compositor/layer.h b/ui/compositor/layer.h
index dc28e09259ed347220dffb0ec2fa61927313c0c6..8b9092b4df7ed1b85b12a6f0685e29becf778c07 100644
--- a/ui/compositor/layer.h
+++ b/ui/compositor/layer.h
@@ -375,8 +375,7 @@ class COMPOSITOR_EXPORT Layer
   // TextureLayerClient
   bool PrepareTextureMailbox(
       cc::TextureMailbox* mailbox,
-      std::unique_ptr<cc::SingleReleaseCallback>* release_callback,
-      bool use_shared_memory) override;
+      std::unique_ptr<cc::SingleReleaseCallback>* release_callback) override;
 
   float device_scale_factor() const { return device_scale_factor_; }