IDL: Put [Exposed=Window] where it's not in Blink's renderer/core/css

Though Web IDL spec removed [PrimaryGlobal] and made [Exposed] required [1],
many blink's IDL files have not followed it yet. So, this CL adds the keyword
to the IDL files which don't have the keyword yet in the renderer/core/css
directory.

[1] https://github.com/heycam/webidl/issues/365

Bug: 963267
Change-Id: I667cab102b9b2cc7ea32ae60aa5de8545b56861d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1640301Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Gyuyoung Kim <gyuyoung@igalia.com>
Cr-Commit-Position: refs/heads/master@{#665462}

third_party/blink/renderer/core/css/css_condition_rule.idl

@@ -4,7 +4,9 @@
 
 // https://drafts.csswg.org/css-conditional/#the-cssconditionrule-interface
 
-interface CSSConditionRule : CSSGroupingRule {
+[
+    Exposed=Window
+] interface CSSConditionRule : CSSGroupingRule {
     // TODO(xing.xu): readonly should be removed.
     readonly attribute DOMString conditionText;
 };

third_party/blink/renderer/core/css/css_font_feature_values_rule.idl

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// https://drafts.csswg.org/css-fonts-4/#om-fontfeaturevalues
+
 [
     RuntimeEnabled=CSSFontFeatureValues
 ] interface CSSFontFeatureValuesRule : CSSRule {

third_party/blink/renderer/core/css/css_keyframe_rule.idl

@@ -28,7 +28,9 @@
 
 // https://drafts.csswg.org/css-animations/#interface-csskeyframerule
 
-interface CSSKeyframeRule : CSSRule {
+[
+    Exposed=Window
+] interface CSSKeyframeRule : CSSRule {
     [RaisesException=Setter] attribute DOMString keyText;
     [SameObject, PutForwards=cssText] readonly attribute CSSStyleDeclaration style;
 };

third_party/blink/renderer/core/css/css_keyframes_rule.idl

@@ -28,7 +28,9 @@
 
 // https://drafts.csswg.org/css-animations/#interface-csskeyframesrule
 
-interface CSSKeyframesRule : CSSRule {
+[
+    Exposed=Window
+] interface CSSKeyframesRule : CSSRule {
     attribute DOMString name;
     readonly attribute CSSRuleList cssRules;
 

third_party/blink/renderer/core/css/css_supports_rule.idl

@@ -28,5 +28,7 @@
 
 // https://drafts.csswg.org/css-conditional/#the-csssupportsrule-interface
 
-interface CSSSupportsRule : CSSConditionRule {
+[
+    Exposed=Window
+] interface CSSSupportsRule : CSSConditionRule {
 };

third_party/blink/renderer/core/css/css_viewport_rule.idl

@@ -30,7 +30,8 @@
 // https://drafts.csswg.org/css-device-adapt/#css-viewport-rule-interface
 
 [
-    RuntimeEnabled=CSSViewport
+    RuntimeEnabled=CSSViewport,
+    Exposed=Window
 ] interface CSSViewportRule : CSSRule {
     readonly attribute CSSStyleDeclaration style;
 };