Add tab characters support in complex path

Source/platform/fonts/shaping/HarfBuzzShaperTest.cpp

Index: Source/platform/fonts/shaping/HarfBuzzShaperTest.cpp
diff --git a/Source/platform/fonts/shaping/HarfBuzzShaperTest.cpp b/Source/platform/fonts/shaping/HarfBuzzShaperTest.cpp
index 0b8dbb3d1ccc8a93de5837c975b188f020b3571c..81a0b7be371f0f647230d149c150a5572f13e883 100644
--- a/Source/platform/fonts/shaping/HarfBuzzShaperTest.cpp
+++ b/Source/platform/fonts/shaping/HarfBuzzShaperTest.cpp
@@ -65,6 +65,99 @@ TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsLeadingCommon)
     EXPECT_EQ(HB_SCRIPT_LATIN, script);
 }
 
+TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsTabOnStart)
+{
+    TextRun leadingTab(reinterpret_cast<const LChar*>("\t//TEST"), 7);
+    leadingTab.setTabSize(true, TabSize(1));
+    HarfBuzzShaper shaper(font, leadingTab, &fallbackFonts);
+    RefPtr<ShapeResult> result = shaper.shapeResult();
+
+    ASSERT_EQ(2u, result->numberOfRunsForTesting());
+    ASSERT_TRUE(result->runInfoForTesting(0, startIndex, numGlyphs, script));
+    EXPECT_EQ(0u, startIndex);
+    EXPECT_EQ(1u, numGlyphs);
+
+    ASSERT_TRUE(result->runInfoForTesting(1, startIndex, numGlyphs, script));
+    EXPECT_EQ(1u, startIndex);
+    EXPECT_EQ(6u, numGlyphs);
+}
+
+TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsTabsOnStart)
+{
+    TextRun leadingTab(reinterpret_cast<const LChar*>("\t\t\tTEST"), 7);
+    leadingTab.setTabSize(true, TabSize(1));
+    HarfBuzzShaper shaper(font, leadingTab, &fallbackFonts);
+    RefPtr<ShapeResult> result = shaper.shapeResult();
+
+    ASSERT_EQ(2u, result->numberOfRunsForTesting());
+    ASSERT_TRUE(result->runInfoForTesting(0, startIndex, numGlyphs, script));
+    EXPECT_EQ(0u, startIndex);
+    EXPECT_EQ(3u, numGlyphs);
+
+    ASSERT_TRUE(result->runInfoForTesting(1, startIndex, numGlyphs, script));
+    EXPECT_EQ(3u, startIndex);
+    EXPECT_EQ(4u, numGlyphs);
+}
+
+TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsTabsOnEnd)
+{
+    TextRun trailingTab(reinterpret_cast<const LChar*>("TEST\t\t\t"), 7);
+    trailingTab.setTabSize(true, TabSize(1));
+    HarfBuzzShaper shaper(font, trailingTab, &fallbackFonts);
+    RefPtr<ShapeResult> result = shaper.shapeResult();
+
+    ASSERT_EQ(2u, result->numberOfRunsForTesting());
+    ASSERT_TRUE(result->runInfoForTesting(0, startIndex, numGlyphs, script));
+    EXPECT_EQ(0u, startIndex);
+    EXPECT_EQ(4u, numGlyphs);
+
+    ASSERT_TRUE(result->runInfoForTesting(1, startIndex, numGlyphs, script));
+    EXPECT_EQ(4u, startIndex);
+    EXPECT_EQ(3u, numGlyphs);
+}
+
+TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsTabsAfterSpaces)
+{
+    TextRun tabsAfterSpaces(reinterpret_cast<const LChar*>("TEST  \t\t\tTEST"), 13);
+    tabsAfterSpaces.setTabSize(true, TabSize(1));
+    HarfBuzzShaper shaper(font, tabsAfterSpaces, &fallbackFonts);
+    RefPtr<ShapeResult> result = shaper.shapeResult();
+
+    ASSERT_EQ(3u, result->numberOfRunsForTesting());
+    ASSERT_TRUE(result->runInfoForTesting(0, startIndex, numGlyphs, script));
+    EXPECT_EQ(0u, startIndex);
+    EXPECT_EQ(6u, numGlyphs);
+
+    ASSERT_TRUE(result->runInfoForTesting(1, startIndex, numGlyphs, script));
+    EXPECT_EQ(6u, startIndex);
+    EXPECT_EQ(3u, numGlyphs);
+
+    ASSERT_TRUE(result->runInfoForTesting(2, startIndex, numGlyphs, script));
+    EXPECT_EQ(9u, startIndex);
+    EXPECT_EQ(4u, numGlyphs);
+}
+
+TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsTabsInMid)
+{
+    TextRun tabsInMid(reinterpret_cast<const LChar*>("TEST\t\t\tTEST"), 11);
+    tabsInMid.setTabSize(true, TabSize(1));
+    HarfBuzzShaper shaper(font, tabsInMid, &fallbackFonts);
+    RefPtr<ShapeResult> result = shaper.shapeResult();
+
+    ASSERT_EQ(3u, result->numberOfRunsForTesting());
+    ASSERT_TRUE(result->runInfoForTesting(0, startIndex, numGlyphs, script));
+    EXPECT_EQ(0u, startIndex);
+    EXPECT_EQ(4u, numGlyphs);
+
+    ASSERT_TRUE(result->runInfoForTesting(1, startIndex, numGlyphs, script));
+    EXPECT_EQ(4u, startIndex);
+    EXPECT_EQ(3u, numGlyphs);
+
+    ASSERT_TRUE(result->runInfoForTesting(2, startIndex, numGlyphs, script));
+    EXPECT_EQ(7u, startIndex);
+    EXPECT_EQ(4u, numGlyphs);
+}
+
 TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsUnicodeVariants)
 {
     struct {