exo: Add zcr_linux_explicit_synchronization_v1

components/exo/buffer.h

Index: components/exo/buffer.h
diff --git a/components/exo/buffer.h b/components/exo/buffer.h
index 42df36ebd80dcfa9358430c7cb10b1e9e082a9eb..6b80c373b308b04a505e1ea5c8e570c2a85a3a97 100644
--- a/components/exo/buffer.h
+++ b/components/exo/buffer.h
@@ -24,6 +24,7 @@ class TextureMailbox;
 }
 
 namespace gfx {
+class GpuFence;
 class GpuMemoryBuffer;
 }
 
@@ -59,6 +60,7 @@ class Buffer : public base::SupportsWeakPtr<Buffer> {
   // |non_client_usage| is true.
   std::unique_ptr<cc::SingleReleaseCallback> ProduceTextureMailbox(
       cc::TextureMailbox* mailbox,
+      gfx::GpuFence* fence,
       bool secure_output_only,
       bool client_usage);