Mac RenderTextHarfBuzz: Use hb_coretext_font_create().

The HarfBuzz roll in r513541 improved Mac UI font support in the
renderer by detecting UI fonts and invoking CTFontCreateUIFontForLanguage().

However, in chrome UI, there is already a CTFont wrapped in a gfx::
PlatformFont for UI fonts. So creating a new CTFont for every hb_shape
call becomes unnecessary and expensive.

hb_coretext_font_create() (after a hb_coretext_face_create()) allows
the steps requiring the call to CTFontCreateUIFontForLanguage() to
be skipped by associating the CTFont with the hb_font_t directly.

Adds a new views_perftest target and LabelPerfTest.GetPreferredSize
to track. On a Late 2013 Mac Pro perf improves from 1390 runs/second
to 3300 runs/second.

+250 runs/second of that comes from a related hotspot in gfx::internal::
CreateSkiaTypeface() which was deriving a new CTFont unnecessarily
before sending it to gfx::CreateHarfBuzzFont().

Bug: 785522
Change-Id: Iccf57fe3fc9a93cd4b9de1e79e81fb84d2ad88bb
Reviewed-on: https://chromium-review.googlesource.com/823743
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526920}

ui/gfx/font.cc

@@ -42,6 +42,9 @@ Font::~Font() {
 }
 
 Font Font::Derive(int size_delta, int style, Font::Weight weight) const {
+  if (size_delta == 0 && style == GetStyle() && weight == GetWeight())
+    return *this;
+
   return platform_font_->DeriveFont(size_delta, style, weight);
 }
 

ui/gfx/harfbuzz_font_skia.cc

@@ -292,7 +292,17 @@ hb_font_t* CreateHarfBuzzFont(sk_sp<SkTypeface> skia_face,
   if (face_cache->first.get() == NULL)
     face_cache->first.Init(skia_face.get());
 
-  hb_font_t* harfbuzz_font = hb_font_create(face_cache->first.get());
+  hb_font_t* harfbuzz_font = nullptr;
+#if defined(OS_MACOSX)
+  // Since we have a CTFontRef available at the right size, associate it with
+  // the hb_font_t. This avoids Harfbuzz doing its own lookup by typeface name,
+  // which requires talking to the font server again.
+  if (CTFontRef ct_font = SkTypeface_GetCTFontRef(skia_face.get()))
+    harfbuzz_font = hb_coretext_font_create(ct_font);
+#endif
+  if (!harfbuzz_font)
+    harfbuzz_font = hb_font_create(face_cache->first.get());
+
   const int scale = SkiaScalarToHarfBuzzUnits(text_size);
   hb_font_set_scale(harfbuzz_font, scale, scale);
   FontData* hb_font_data = new FontData(&face_cache->second);

ui/views/BUILD.gn

@@ -1177,3 +1177,18 @@ source_set("views_interactive_ui_tests") {
     sources -= [ "corewm/desktop_capture_controller_unittest.cc" ]
   }
 }
+
+test("views_perftests") {
+  sources = [
+    "controls/label_perftest.cc",
+    "views_perftests.cc",
+  ]
+
+  deps = [
+    ":test_support",
+    "//base/test:test_support",
+    "//cc/base:base",
+    "//testing/perf",
+    "//ui/resources:ui_test_pak",
+  ]
+}

ui/views/DEPS

@@ -31,13 +31,16 @@ specific_include_rules = {
   "run_all_unittests_main\.cc": [
     "+mojo/edk/embedder",
   ],
+  "views_perftests\.cc": [
+    "+mojo/edk/embedder",
+  ],
   "view_unittest\.cc": [
     "+cc/playback"
   ],
   "views_test_suite\.cc": [
     "+gpu/ipc/service",
   ],
-  "paint_info_unittest\.cc": [
+  ".*test\.cc": [
     "+cc/base",
   ]
 }

ui/views/controls/label_perftest.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/controls/label.h"
+
+#include "base/strings/utf_string_conversions.h"
+#include "cc/base/lap_timer.h"
+#include "testing/perf/perf_test.h"
+#include "ui/views/test/views_test_base.h"
+
+namespace views {
+
+using LabelPerfTest = ViewsTestBase;
+
+// Test the number of text size measurements that can be made made per second.
+// This should surface any performance regressions in underlying text layout
+// system, e.g., failure to cache font structures.
+TEST_F(LabelPerfTest, GetPreferredSize) {
+  Label label;
+
+  // Alternate between two strings to ensure caches are cleared.
+  base::string16 string1 = base::ASCIIToUTF16("boring ascii string");
+  base::string16 string2 = base::ASCIIToUTF16("another uninteresting sequence");
+
+  constexpr int kLaps = 5000;  // Aim to run in under 3 seconds.
+  constexpr int kWarmupLaps = 5;
+
+  // The time limit is unused. Use kLaps for the check interval so the time is
+  // only measured once.
+  cc::LapTimer timer(kWarmupLaps, base::TimeDelta(), kLaps);
+  for (int i = 0; i < kLaps + kWarmupLaps; ++i) {
+    label.SetText(i % 2 == 0 ? string1 : string2);
+    label.GetPreferredSize();
+    timer.NextLap();
+  }
+  perf_test::PrintResult("LabelPerfTest", std::string(), "GetPreferredSize",
+                         timer.LapsPerSecond(), "runs/s", true);
+}
+
+}  // namespace views

ui/views/views_perftests.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/test/launcher/unit_test_launcher.h"
+#include "ui/views/views_test_suite.h"
+
+int main(int argc, char** argv) {
+  views::ViewsTestSuite test_suite(argc, argv);
+  return base::LaunchUnitTestsSerially(
+      argc, argv,
+      base::Bind(&views::ViewsTestSuite::Run, base::Unretained(&test_suite)));
+}