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 a2b76d0ce99aeea5d162dfb0131e29f736337ae8..3e8b5d871cca250f1e386b6d006b944e981eff4a 100644
--- a/ui/aura/mus/window_tree_client_unittest.cc
+++ b/ui/aura/mus/window_tree_client_unittest.cc
@@ -104,16 +104,19 @@ std::vector<uint8_t> ConvertToPropertyTransportValue(int64_t value) {
 using WindowTreeClientWmTest = test::AuraMusWmTestBase;
 using WindowTreeClientClientTest = test::AuraMusClientTestBase;
 
-// WindowTreeClientWmTest with --enable-surface-synchronization.
-class WindowTreeClientWmTestSurfaceSync : public WindowTreeClientWmTest {
+class WindowTreeClientWmTestSurfaceSync
+    : public WindowTreeClientWmTest,
+      public ::testing::WithParamInterface<bool> {
  public:
   WindowTreeClientWmTestSurfaceSync() {}
   ~WindowTreeClientWmTestSurfaceSync() override {}
 
   // WindowTreeClientWmTest:
   void SetUp() override {
-    base::CommandLine::ForCurrentProcess()->AppendSwitch(
-        cc::switches::kEnableSurfaceSynchronization);
+    if (GetParam()) {
+      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+          switches::kForceDeviceScaleFactor, "2");
+    }
     WindowTreeClientWmTest::SetUp();
   }
 
@@ -204,9 +207,13 @@ TEST_F(WindowTreeClientWmTest, SetBoundsFailedLocalSurfaceId) {
   EXPECT_FALSE(window_mus->GetLocalSurfaceId().is_valid());
 }
 
+INSTANTIATE_TEST_CASE_P(/* no prefix */,
+                        WindowTreeClientWmTestSurfaceSync,
+                        ::testing::Bool());
+
 // Verifies that a ClientSurfaceEmbedder is created for a window once it has
 // a bounds, and a valid FrameSinkId.
-TEST_F(WindowTreeClientWmTestSurfaceSync,
+TEST_P(WindowTreeClientWmTestSurfaceSync,
        ClientSurfaceEmbedderOnValidEmbedding) {
   Window window(nullptr);
   // TOP_LEVEL_IN_WM and EMBED_IN_OWNER windows allocate cc::LocalSurfaceIds
@@ -219,7 +226,7 @@ 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 +247,14 @@ 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
@@ -256,11 +265,30 @@ 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
 // the size changes, but not when the position changes.
-TEST_F(WindowTreeClientWmTest, SetBoundsLocalSurfaceIdChanges) {
+TEST_P(WindowTreeClientWmTestSurfaceSync, SetBoundsLocalSurfaceIdChanges) {
   ASSERT_EQ(base::nullopt, window_tree()->last_local_surface_id());
   Window window(nullptr);
   // TOP_LEVEL_IN_WM and EMBED_IN_OWNER windows allocate cc::LocalSurfaceIds