Leave out the default value when serializing font-feature-settings

According to the shortest-serialization principle [1], values should be
omitted if their omission wouldn't change the value of reparsing. As
"1"/"on" is the default value for font-feature-settings, omit this when
serializing, matching the behavior of Firefox.

[1]: https://github.com/w3c/csswg-drafts/issues/1564

Bug: 807744
Change-Id: Ieb8b86aa66aa303a82a895c42373177cf7f13d07
Reviewed-on: https://chromium-review.googlesource.com/896203Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: Chris Nardi <cnardi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533566}

third_party/WebKit/LayoutTests/css3/font-feature-settings-parsing-expected.txt

@@ -5,16 +5,16 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 
 - Tests valid inputs.
 PASS parseResultOf("valid_normal") is "normal"
-PASS parseResultOf("valid_value_1") is "\"dlig\" 1"
+PASS parseResultOf("valid_value_1") is "\"dlig\""
 PASS parseResultOf("valid_value_2") is "\"swsh\" 2"
-PASS parseResultOf("valid_value_on") is "\"smcp\" 1"
+PASS parseResultOf("valid_value_on") is "\"smcp\""
 PASS parseResultOf("valid_value_off") is "\"liga\" 0"
-PASS parseResultOf("valid_value_omit") is "\"c2sc\" 1"
-PASS parseResultOf("valid_valuelist") is "\"tnum\" 1, \"hist\" 1"
-PASS parseResultOf("valid_singlequote") is "\"PKRN\" 1"
-PASS parseResultOf("valid_unusual_tag") is "\"!@#$\" 1"
-PASS parseResultOf("valid_tag_space") is "\"a bc\" 1"
-PASS parseResultOf("valid_composite") is "\"dlig\" 1, \"smcp\" 1, \"lig \" 0"
+PASS parseResultOf("valid_value_omit") is "\"c2sc\""
+PASS parseResultOf("valid_valuelist") is "\"tnum\", \"hist\""
+PASS parseResultOf("valid_singlequote") is "\"PKRN\""
+PASS parseResultOf("valid_unusual_tag") is "\"!@#$\""
+PASS parseResultOf("valid_tag_space") is "\"a bc\""
+PASS parseResultOf("valid_composite") is "\"dlig\", \"smcp\", \"lig \" 0"
 - Tests invalid inputs.  Results should be "normal".
 PASS parseResultOf("invalid_ident") is "normal"
 PASS parseResultOf("invalid_cases") is "normal"
@@ -34,10 +34,10 @@ PASS parseResultOf("invalid_beginning_comma") is "normal"
 PASS parseResultOf("invalid_on") is "normal"
 PASS parseResultOf("invalid_0") is "normal"
 - Tests inherit.
-PASS parseResultOf("outer") is "\"dlig\" 1"
-PASS parseResultOf("inner") is "\"dlig\" 1"
+PASS parseResultOf("outer") is "\"dlig\""
+PASS parseResultOf("inner") is "\"dlig\""
 - Tests @font-face.
-PASS fontFaceRuleValid is "\"liga\" 1"
+PASS fontFaceRuleValid is "\"liga\""
 PASS fontFaceRuleInvalid is ""
 PASS successfullyParsed is true
 

third_party/WebKit/LayoutTests/css3/font-feature-settings-parsing.html

@@ -175,16 +175,16 @@ function parseResultOf(id) {
 
 debug('- Tests valid inputs.');
 shouldBeEqualToString('parseResultOf("valid_normal")', "normal");
-shouldBeEqualToString('parseResultOf("valid_value_1")', '"dlig" 1');
+shouldBeEqualToString('parseResultOf("valid_value_1")', '"dlig"');
 shouldBeEqualToString('parseResultOf("valid_value_2")', '"swsh" 2');
-shouldBeEqualToString('parseResultOf("valid_value_on")', '"smcp" 1');
+shouldBeEqualToString('parseResultOf("valid_value_on")', '"smcp"');
 shouldBeEqualToString('parseResultOf("valid_value_off")', '"liga" 0');
-shouldBeEqualToString('parseResultOf("valid_value_omit")', '"c2sc" 1');
-shouldBeEqualToString('parseResultOf("valid_valuelist")', '"tnum" 1, "hist" 1');
-shouldBeEqualToString('parseResultOf("valid_singlequote")', '"PKRN" 1');
-shouldBeEqualToString('parseResultOf("valid_unusual_tag")', '"!@#$" 1');
-shouldBeEqualToString('parseResultOf("valid_tag_space")', '"a bc" 1');
-shouldBeEqualToString('parseResultOf("valid_composite")', '"dlig" 1, "smcp" 1, "lig " 0');
+shouldBeEqualToString('parseResultOf("valid_value_omit")', '"c2sc"');
+shouldBeEqualToString('parseResultOf("valid_valuelist")', '"tnum", "hist"');
+shouldBeEqualToString('parseResultOf("valid_singlequote")', '"PKRN"');
+shouldBeEqualToString('parseResultOf("valid_unusual_tag")', '"!@#$"');
+shouldBeEqualToString('parseResultOf("valid_tag_space")', '"a bc"');
+shouldBeEqualToString('parseResultOf("valid_composite")', '"dlig", "smcp", "lig " 0');
 
 debug('- Tests invalid inputs.  Results should be "normal".');
 shouldBe('parseResultOf("invalid_ident")', '"normal"');
@@ -206,13 +206,13 @@ shouldBe('parseResultOf("invalid_on")', '"normal"');
 shouldBe('parseResultOf("invalid_0")', '"normal"');
 
 debug('- Tests inherit.');
-shouldBeEqualToString('parseResultOf("outer")', '"dlig" 1');
-shouldBeEqualToString('parseResultOf("inner")', '"dlig" 1');
+shouldBeEqualToString('parseResultOf("outer")', '"dlig"');
+shouldBeEqualToString('parseResultOf("inner")', '"dlig"');
 
 debug('- Tests @font-face.');
 var fontFaceRuleValid = document.styleSheets[1].cssRules[0].style['-webkit-font-feature-settings'];
 var fontFaceRuleInvalid = document.styleSheets[1].cssRules[1].style['-webkit-font-feature-settings'];
-shouldBeEqualToString('fontFaceRuleValid', '"liga" 1');
+shouldBeEqualToString('fontFaceRuleValid', '"liga"');
 shouldBeEqualToString('fontFaceRuleInvalid', "");
 
 </script>

third_party/WebKit/LayoutTests/css3/fonts/font-feature-settings-parsing-prefixed-expected.txt

 This is a testharness.js-based test.
-Harness Error. harness_status.status = 1 , harness_status.message = 2 duplicate test names: "fontFeatureSettings of '@font-face { font-feature-settings: "smcp" 1; }' should be '"smcp" 1'", "webkitFontFeatureSettings of '@font-face { font-feature-settings: "smcp" 1; }' should be '"smcp" 1'"
+Harness Error. harness_status.status = 1 , harness_status.message = 2 duplicate test names: "fontFeatureSettings of '@font-face { font-feature-settings: "smcp"; }' should be '"smcp"'", "webkitFontFeatureSettings of '@font-face { font-feature-settings: "smcp"; }' should be '"smcp"'"
 PASS 'fontFeatureSettings' in style
 PASS 'webkitFontFeatureSettings' in style
-PASS fontFeatureSettings of '@font-face { font-feature-settings: "smcp" 1; }' should be '"smcp" 1'
-PASS webkitFontFeatureSettings of '@font-face { font-feature-settings: "smcp" 1; }' should be '"smcp" 1'
-PASS fontFeatureSettings of '@font-face { font-feature-settings: "smcp" 1; }' should be '"smcp" 1'
-PASS webkitFontFeatureSettings of '@font-face { font-feature-settings: "smcp" 1; }' should be '"smcp" 1'
-PASS fontFeatureSettings of 'font-feature-settings:"smcp" 1' should be '"smcp" 1'
-PASS webkitFontFeatureSettings of 'font-feature-settings:"smcp" 1' should be '"smcp" 1'
-PASS fontFeatureSettings of '-webkit-font-feature-settings:"smcp" 1' should be '"smcp" 1'
-PASS webkitFontFeatureSettings of '-webkit-font-feature-settings:"smcp" 1' should be '"smcp" 1'
+PASS fontFeatureSettings of '@font-face { font-feature-settings: "smcp"; }' should be '"smcp"'
+PASS webkitFontFeatureSettings of '@font-face { font-feature-settings: "smcp"; }' should be '"smcp"'
+PASS fontFeatureSettings of '@font-face { font-feature-settings: "smcp"; }' should be '"smcp"'
+PASS webkitFontFeatureSettings of '@font-face { font-feature-settings: "smcp"; }' should be '"smcp"'
+PASS fontFeatureSettings of 'font-feature-settings:"smcp" 1' should be '"smcp"'
+PASS webkitFontFeatureSettings of 'font-feature-settings:"smcp" 1' should be '"smcp"'
+PASS fontFeatureSettings of '-webkit-font-feature-settings:"smcp" 1' should be '"smcp"'
+PASS webkitFontFeatureSettings of '-webkit-font-feature-settings:"smcp" 1' should be '"smcp"'
 Harness: the test ran to completion.
 

third_party/WebKit/LayoutTests/css3/fonts/font-feature-settings-parsing-prefixed.html

@@ -12,7 +12,7 @@
 <div style='font-feature-settings:"smcp" 1'></div>
 <div style='-webkit-font-feature-settings:"smcp" 1'></div>
 <script>
-var expected = '"smcp" 1';
+var expected = '"smcp"';
 
 var style = document.createElement("foo").style;
 test(function () {

third_party/WebKit/LayoutTests/external/wpt/css/css-fonts/font-feature-settings-serialization-001.html

@@ -20,7 +20,7 @@
     const div = document.querySelector("#test");
     const div1 = document.querySelector("#test1");
     test(function() {
-        assert_equals(getComputedStyle(div).fontFeatureSettings, '"vert" 1');
-        assert_equals(getComputedStyle(div1).fontFeatureSettings, '"vert" 1');
-    }, "font-feature-settings should have its feature tag serialized with double quotes");
+        assert_equals(getComputedStyle(div).fontFeatureSettings, '"vert"');
+        assert_equals(getComputedStyle(div1).fontFeatureSettings, '"vert"');
+    }, "font-feature-settings should be serialized with double quotes, and the default value of 1 should be omitted");
 </script>

third_party/WebKit/LayoutTests/fast/css/fontface-properties-expected.txt

@@ -8,7 +8,7 @@ PASS ahemFace.style is "italic"
 PASS ahemFace.weight is "300"
 PASS ahemFace.unicodeRange is "U+0-3FF"
 PASS ahemFace.variant is "small-caps"
-PASS ahemFace.featureSettings is "\"dlig\" 1"
+PASS ahemFace.featureSettings is "\"dlig\""
 PASS ahemFace.display is "block"
 
 PASS defaultFace.family is "defaultFace"
@@ -33,7 +33,7 @@ PASS modifiedFace.style is "italic"
 PASS modifiedFace.weight is "900"
 PASS modifiedFace.unicodeRange is "U+0-3FF"
 PASS modifiedFace.variant is "small-caps"
-PASS modifiedFace.featureSettings is "\"dlig\" 1, \"liga\" 0"
+PASS modifiedFace.featureSettings is "\"dlig\", \"liga\" 0"
 PASS modifiedFace.display is "fallback"
 
 PASS face.style = '' threw exception SyntaxError: Failed to set the 'style' property on 'FontFace': Failed to set '' as a property value..

third_party/WebKit/LayoutTests/fast/css/fontface-properties.html

@@ -31,7 +31,7 @@ function runTests() {
     shouldBeEqualToString('ahemFace.weight', '300');
     shouldBeEqualToString('ahemFace.unicodeRange', 'U+0-3FF');
     shouldBeEqualToString('ahemFace.variant', 'small-caps');
-    shouldBeEqualToString('ahemFace.featureSettings', '"dlig" 1');
+    shouldBeEqualToString('ahemFace.featureSettings', '"dlig"');
     shouldBeEqualToString('ahemFace.display', 'block');
 
     debug('');
@@ -76,7 +76,7 @@ function runTests() {
     shouldBeEqualToString('modifiedFace.weight', '900');
     shouldBeEqualToString('modifiedFace.unicodeRange', 'U+0-3FF');
     shouldBeEqualToString('modifiedFace.variant', 'small-caps');
-    shouldBeEqualToString('modifiedFace.featureSettings', '"dlig" 1, "liga" 0');
+    shouldBeEqualToString('modifiedFace.featureSettings', '"dlig", "liga" 0');
     shouldBeEqualToString('modifiedFace.display', 'fallback');
 
     debug('');

third_party/WebKit/LayoutTests/fast/css/inherited-properties-rare-text-expected.txt

-test1 -webkit-font-feature-settings: "dlig" 1
+test1 -webkit-font-feature-settings: "dlig"
 test2 -webkit-font-feature-settings: normal
 test1 -webkit-font-smoothing: antialiased
 test2 -webkit-font-smoothing: auto

third_party/WebKit/Source/core/css/CSSFontFeatureValue.cpp

@@ -37,8 +37,12 @@ String CSSFontFeatureValue::CustomCSSText() const {
   StringBuilder builder;
   builder.Append('"');
   builder.Append(tag_);
-  builder.Append("\" ");
-  builder.AppendNumber(value_);
+  builder.Append('"');
+  // Omit the value if it's 1 as 1 is implied by default.
+  if (value_ != 1) {
+    builder.Append(' ');
+    builder.AppendNumber(value_);
+  }
   return builder.ToString();
 }