Re-enable layout provider unittests

This CL is re-enabling the layout unittest on windows.

Fonts size have been adjusted on MAC. They are now about
1 pixel larger than other platform, which make more sense
than the previous values. I cannot explain the choice of
the previous values.

These tests were flaky because some code in chrome tests were
modifying a system-wide flag that change the way fonts are
rendered.

We are assuming the default configuration: Anti-Aliasing is on.

Other unittests should not turn on/off the system-wide flag.
Modifying that flag may leave the developer computer or the
build bot in a bad state. Tests are likely to crash and may
not restore correctly the state; they may run in parallel and
have incorrect behavior.

This change needs to be landed after fixing flakiness:
  1) https://chromium-review.googlesource.com/c/chromium/src/+/1570527/
  2) https://chromium-review.googlesource.com/c/chromium/src/+/1569969

NOTE TO SHERRIFS:
 If any Layout test are flaky, please disable the test
 and assign the bug to me. I think I've found any cause of flakiness. If not,
 I'll dig more.

BUG=759870, 701241
R=tapted@chromium.org
CC=​​​​​​​​​robliao@chromium.org,asvitkine@chromium.org

Change-Id: Iab8f4adb58e565600bedecb1365e05bfdf931079
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1570653
Commit-Queue: Etienne Bergeron <etienneb@chromium.org>
Reviewed-by: Etienne Bergeron <etienneb@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658689}

chrome/browser/ui/views/chrome_typography_provider.cc

@@ -110,18 +110,17 @@ SkColor GetHarmonyTextColorForNonStandardNativeTheme(
 #if defined(OS_WIN)
 // static
 int ChromeTypographyProvider::GetPlatformFontHeight(int font_context) {
-  const bool windows_10 = base::win::GetVersion() >= base::win::Version::WIN10;
   switch (font_context) {
     case CONTEXT_HEADLINE:
-      return windows_10 ? 27 : 28;
+      return 27;
     case views::style::CONTEXT_DIALOG_TITLE:
-      return windows_10 ? 20 : 21;
+      return 20;
     case CONTEXT_BODY_TEXT_LARGE:
     case CONTEXT_TAB_HOVER_CARD_TITLE:
     case views::style::CONTEXT_MESSAGE_BOX_BODY_TEXT:
       return 18;
     case CONTEXT_BODY_TEXT_SMALL:
-      return windows_10 ? 16 : 15;
+      return 16;
   }
   NOTREACHED();
   return 0;

chrome/browser/ui/views/layout_provider_unittest.cc

@@ -39,17 +39,22 @@ class LayoutProviderTest : public testing::Test {
  public:
   LayoutProviderTest() {}
 
-#if defined(OS_WIN)
  protected:
   static void SetUpTestCase() {
-    // The expected case is to have DirectWrite enabled; the fallback gives
-    // different font heights. However, only use DirectWrite on Windows 10 and
-    // later, since it's known to have flaky results on Windows 7. See
-    // http://crbug.com/759870.
-    if (base::win::GetVersion() >= base::win::Version::WIN10)
-      gfx::win::InitializeDirectWrite();
-  }
+#if defined(OS_WIN)
+    gfx::win::InitializeDirectWrite();
+
+    // Ensures anti-aliasing is activated.
+    BOOL antialiasing = TRUE;
+    BOOL result =
+        SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &antialiasing, 0);
+    ASSERT_NE(result, FALSE);
+    ASSERT_NE(antialiasing, FALSE)
+        << "The test requires that fonts smoothing (anti-aliasing) is "
+           "activated. If this assert is failing you need to manually activate "
+           "the flag in your system fonts settings.";
 #endif
+  }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LayoutProviderTest);
@@ -58,23 +63,24 @@ class LayoutProviderTest : public testing::Test {
 // Check legacy font sizes. No new code should be using these constants, but if
 // these tests ever fail it probably means something in the old UI will have
 // changed by mistake.
-// Disabled since this relies on machine configuration. http://crbug.com/701241.
-TEST_F(LayoutProviderTest, DISABLED_LegacyFontSizeConstants) {
+TEST_F(LayoutProviderTest, LegacyFontSizeConstants) {
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
   gfx::FontList label_font = rb.GetFontListWithDelta(ui::kLabelFontSizeDelta);
 
-  EXPECT_EQ(12, label_font.GetFontSize());
+#if defined(OS_WIN)
+  EXPECT_EQ(16, label_font.GetHeight());
+  EXPECT_EQ(13, label_font.GetBaseline());
+#else
   EXPECT_EQ(15, label_font.GetHeight());
   EXPECT_EQ(12, label_font.GetBaseline());
+#endif
+  EXPECT_EQ(12, label_font.GetFontSize());
   EXPECT_EQ(9, label_font.GetCapHeight());
-// Note some Windows bots report 11,13,11,9 for the above.
-// TODO(tapted): Smoke them out and figure out why.
 
 #if defined(OS_MACOSX)
-  EXPECT_EQ(10, label_font.GetExpectedTextWidth(1));
+  EXPECT_EQ(7, label_font.GetExpectedTextWidth(1));
 #else
   EXPECT_EQ(6, label_font.GetExpectedTextWidth(1));
-// Some Windows bots may say 5.
 #endif
 
   gfx::FontList title_font = rb.GetFontListWithDelta(ui::kTitleFontSizeDelta);
@@ -104,7 +110,7 @@ TEST_F(LayoutProviderTest, DISABLED_LegacyFontSizeConstants) {
   if (base::mac::IsOS10_9()) {
     EXPECT_EQ(7, title_font.GetExpectedTextWidth(1));
   } else {
-    EXPECT_EQ(12, title_font.GetExpectedTextWidth(1));
+    EXPECT_EQ(8, title_font.GetExpectedTextWidth(1));
   }
 #else
   EXPECT_EQ(8, title_font.GetExpectedTextWidth(1));
@@ -142,8 +148,7 @@ TEST_F(LayoutProviderTest, DISABLED_LegacyFontSizeConstants) {
 // platform starts returning 18 in a standard configuration then the
 // TypographyProvider must add 4 instead. We do this so that Chrome adapts
 // correctly to _non-standard_ system font configurations on user machines.
-// Disabled since this relies on machine configuration. http://crbug.com/701241.
-TEST_F(LayoutProviderTest, DISABLED_RequestFontBySize) {
+TEST_F(LayoutProviderTest, RequestFontBySize) {
 #if defined(OS_MACOSX)
   constexpr int kBase = 13;
 #else
@@ -311,8 +316,7 @@ TEST_F(LayoutProviderTest, TypographyLineHeight) {
 // Ensure that line heights reported in a default bot configuration match the
 // Harmony spec. This test will only run if it detects that the current machine
 // has the default OS configuration.
-// Flaky. http://crbug.com/759870
-TEST_F(LayoutProviderTest, DISABLED_ExplicitTypographyLineHeight) {
+TEST_F(LayoutProviderTest, ExplicitTypographyLineHeight) {
   std::unique_ptr<views::LayoutProvider> layout_provider =
       ChromeLayoutProvider::CreateLayoutProvider();