exo: Implement zcr_linux_explicit_synchronization_v1

components/exo/display_unittest.cc

Index: components/exo/display_unittest.cc
diff --git a/components/exo/display_unittest.cc b/components/exo/display_unittest.cc
index 694915dbf624be1dba91dbfc994756c9c6810081..ac29c755f917bca935f6b892c574f9999519d71b 100644
--- a/components/exo/display_unittest.cc
+++ b/components/exo/display_unittest.cc
@@ -86,6 +86,35 @@ TEST_F(DisplayTest, DISABLED_CreateLinuxDMABufBuffer) {
   EXPECT_FALSE(buffer2);
 }
 
+TEST_F(DisplayTest, CreateLinuxFence) {
+  int sockets_unscoped[2];
+
+  ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM, 0, fds));
+
+  // Emulate the behaviour of a fence FD (returns POLLIN when signaled) using
+  // a socket pair.
+  Base::ScopedFD socket_waitee(sockets_unscoped[0]);
+
+  std::unique_ptr<gfx::GpuFence> fence1 =
+      display->CreateLinuxFence(sockets_unscoped[1]);
+  EXPECT_TRUE(fence1);

[reveman, 2016/10/12 19:20:19]

nit: ASSERT_TRUE as code below will crash if this fails

+  close(sockets_unscoped[1]);
+
+  // The fence must be unsignaled when we start.
+  EXPECT_FALSE(fence1->Wait(TimeDelta::FromMilliseconds(50)));
+
+  // Unblock the fence, and make sure this signals success.
+  uint32_t dummy = 1;
+  ASSERT_EQ(sizeof(dummy), UnixDomainSocket::SendMsg(socket_waitee, &dummy,
+                                                     sizeof(dummy), nullptr));
+
+  EXPECT_TRUE(fence1->Wait(TimeDelta::FromMilliseconds(50)));
+
+  std::unique_ptr<gfx::GpuFence> fence2 =

[reveman, 2016/10/12 19:20:19]

nit: just a short comment here to explain that this checks that an invalid fence
is not causing bad behavior

+      display->CreateLinuxFence(-1);
+  EXPECT_FALSE(fence2);
+}
+
 // TODO(dcastagna): Add YV12 unittest once we can allocate the buffer
 // via Ozone. crbug.com/618516