Aura-Mus: Fix high-DPI gutter

ui/aura/mus/window_tree_client_unittest.cc

Index: ui/aura/mus/window_tree_client_unittest.cc
diff --git a/ui/aura/mus/window_tree_client_unittest.cc b/ui/aura/mus/window_tree_client_unittest.cc
index 887b9927c7729eb1cf20f09f77b473ab5a3aa265..ccd9db5d38e4fbdbc66b7e6211ad5d0eb52d1ae1 100644
--- a/ui/aura/mus/window_tree_client_unittest.cc
+++ b/ui/aura/mus/window_tree_client_unittest.cc
@@ -114,6 +114,8 @@ class WindowTreeClientWmTestSurfaceSync : public WindowTreeClientWmTest {
   void SetUp() override {
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         cc::switches::kEnableSurfaceSynchronization);
+    base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+        switches::kForceDeviceScaleFactor, "2");

[sadrul, 2017/05/09 15:04:59]

This makes all tests run in high-dpi. Can you create a subclass from here for
the gutter test that adds the DSF 2?

Or make all these tests parameterized on DSF ... although that may be going a
bit overboard.

[Fady Samuel, 2017/05/30 21:30:08]

Done.

     WindowTreeClientWmTest::SetUp();
   }
 
@@ -219,7 +221,7 @@ TEST_F(WindowTreeClientWmTestSurfaceSync,
   WindowMus* window_mus = WindowMus::Get(&window);
   ASSERT_NE(nullptr, window_mus);
   EXPECT_FALSE(window_mus->GetLocalSurfaceId().is_valid());
-  const gfx::Rect new_bounds(gfx::Rect(0, 0, 100, 100));
+  gfx::Rect new_bounds(gfx::Rect(0, 0, 100, 100));
   ASSERT_NE(new_bounds, window.bounds());
   window.SetBounds(new_bounds);
   EXPECT_EQ(new_bounds, window.bounds());
@@ -240,12 +242,14 @@ TEST_F(WindowTreeClientWmTestSurfaceSync,
   ASSERT_NE(nullptr, client_surface_embedder);
 
   // Until the fallback surface fills the window, we will have gutter.
-  ui::Layer* right_gutter = client_surface_embedder->RightGutterForTesting();
-  ASSERT_NE(nullptr, right_gutter);
-  EXPECT_EQ(gfx::Rect(100, 100), right_gutter->bounds());
-  // We don't have a bottom gutter if the fallback surface size is (0, 0) as the
-  // right gutter will fill the whole area.
-  ASSERT_EQ(nullptr, client_surface_embedder->BottomGutterForTesting());
+  {
+    ui::Layer* right_gutter = client_surface_embedder->RightGutterForTesting();
+    ASSERT_NE(nullptr, right_gutter);
+    EXPECT_EQ(gfx::Rect(100, 100), right_gutter->bounds());
+    // We don't have a bottom gutter if the fallback surface size is (0, 0) as
+    // the right gutter will fill the whole area.
+    ASSERT_EQ(nullptr, client_surface_embedder->BottomGutterForTesting());
+  }
 
   // When a SurfaceInfo arrives from the window server, we use it as the
   // fallback SurfaceInfo. Here we issue the PrimarySurfaceInfo back to the
@@ -256,6 +260,25 @@ TEST_F(WindowTreeClientWmTestSurfaceSync,
   // The gutter is gone.
   ASSERT_EQ(nullptr, client_surface_embedder->BottomGutterForTesting());
   ASSERT_EQ(nullptr, client_surface_embedder->RightGutterForTesting());
+
+  // Resize again: we should have gutter.
+  new_bounds.SetRect(0, 0, 150, 150);
+  ASSERT_NE(new_bounds, window.bounds());
+  window.SetBounds(new_bounds);
+  ASSERT_NE(nullptr, client_surface_embedder->BottomGutterForTesting());
+  ASSERT_NE(nullptr, client_surface_embedder->RightGutterForTesting());
+
+  // Until the fallback surface fills the window, we will have gutter.
+  {
+    ui::Layer* right_gutter = client_surface_embedder->RightGutterForTesting();
+    ASSERT_NE(nullptr, right_gutter);
+    EXPECT_EQ(gfx::Rect(100, 0, 50, 150), right_gutter->bounds());
+
+    ui::Layer* bottom_gutter =
+        client_surface_embedder->BottomGutterForTesting();
+    ASSERT_NE(nullptr, bottom_gutter);
+    EXPECT_EQ(gfx::Rect(0, 100, 100, 50), bottom_gutter->bounds());
+  }
 }
 
 // Verifies that the cc::LocalSurfaceId generated by an embedder changes when