Serialize 'oblique' computed values for 'font-style'

Handling of 'oblique' values were missing in
ComputedStyleUtils::ValueForFontStyle - serialize as 'oblique <angle>'.
Because of this the return value needs to be widened to CSSValue.

Bug: 809935, 809938
Change-Id: I1de846595ed955455d57ab9f6ea45326e502a65b
Reviewed-on: https://chromium-review.googlesource.com/995273Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#548044}

third_party/WebKit/LayoutTests/TestExpectations

@@ -2264,9 +2264,8 @@ crbug.com/626703 [ Debug ] external/wpt/html/semantics/tabular-data/processing-m
 crbug.com/666993 external/wpt/requestidlecallback/callback-idle-periods.html [ Timeout ]
 
 # Crashes with DCHECK enabled, but not on normal Release builds.
-crbug.com/828746 external/wpt/css/css-fonts/variations/font-shorthand.html [ Pass Crash Failure ]
-crbug.com/828746 external/wpt/css/css-fonts/variations/font-style-interpolation.html [ Pass Crash Timeout ]
-crbug.com/828747 external/wpt/css/css-fonts/variations/font-weight-lighter-bolder.html [ Pass Crash Failure ]
+crbug.com/809935 external/wpt/css/css-fonts/variations/font-style-interpolation.html [ Timeout ]
+crbug.com/828748 external/wpt/css/css-fonts/variations/font-weight-lighter-bolder.html [ Pass Crash Failure ]
 crbug.com/626703 external/wpt/css/css-ui/text-overflow-011.html [ Failure Crash Pass ]
 crbug.com/626703 external/wpt/workers/opaque-origin.html [ Failure Crash Timeout ]
 crbug.com/626703 external/wpt/html/rendering/non-replaced-elements/margin-collapsing-quirks/multicol-quirks-mode.html [ Pass Crash ]

third_party/WebKit/Source/core/css/properties/ComputedStyleUtils.cpp

@@ -11,6 +11,7 @@
 #include "core/css/CSSCounterValue.h"
 #include "core/css/CSSCustomIdentValue.h"
 #include "core/css/CSSFontFamilyValue.h"
+#include "core/css/CSSFontStyleRangeValue.h"
 #include "core/css/CSSFunctionValue.h"
 #include "core/css/CSSGridLineNamesValue.h"
 #include "core/css/CSSInitialValue.h"
@@ -745,8 +746,7 @@ CSSPrimitiveValue* ComputedStyleUtils::ValueForFontStretch(
                                    CSSPrimitiveValue::UnitType::kPercentage);
 }
 
-CSSIdentifierValue* ComputedStyleUtils::ValueForFontStyle(
-    const ComputedStyle& style) {
+CSSValue* ComputedStyleUtils::ValueForFontStyle(const ComputedStyle& style) {
   FontSelectionValue angle = style.GetFontDescription().Style();
   if (angle == NormalSlopeValue()) {
     return CSSIdentifierValue::Create(CSSValueNormal);
@@ -756,8 +756,14 @@ CSSIdentifierValue* ComputedStyleUtils::ValueForFontStyle(
     return CSSIdentifierValue::Create(CSSValueItalic);
   }
 
-  NOTREACHED();
-  return CSSIdentifierValue::Create(CSSValueNormal);
+  // The spec says: 'The lack of a number represents an angle of
+  // "20deg"', but since we compute that to 'italic' (handled above),
+  // we don't perform any special treatment of that value here.
+  CSSValueList* oblique_values = CSSValueList::CreateSpaceSeparated();
+  oblique_values->Append(
+      *CSSPrimitiveValue::Create(angle, CSSPrimitiveValue::UnitType::kDegrees));
+  return CSSFontStyleRangeValue::Create(
+      *CSSIdentifierValue::Create(CSSValueOblique), *oblique_values);
 }
 
 CSSPrimitiveValue* ComputedStyleUtils::ValueForFontWeight(

third_party/WebKit/Source/core/css/properties/ComputedStyleUtils.h

@@ -102,7 +102,7 @@ class ComputedStyleUtils {
   static CSSValueList* ValueForFontFamily(const ComputedStyle&);
   static CSSPrimitiveValue* ValueForFontSize(const ComputedStyle&);
   static CSSPrimitiveValue* ValueForFontStretch(const ComputedStyle&);
-  static CSSIdentifierValue* ValueForFontStyle(const ComputedStyle&);
+  static CSSValue* ValueForFontStyle(const ComputedStyle&);
   static CSSPrimitiveValue* ValueForFontWeight(const ComputedStyle&);
   static CSSIdentifierValue* ValueForFontVariantCaps(const ComputedStyle&);
   static CSSValue* ValueForFontVariantLigatures(const ComputedStyle&);