Implement all shorthand property.

LayoutTests/fast/css/all-shorthand-css-text-expected.txt

+Test for crbug.com/172051: all shorthand property.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS cssRules.length is 11
+PASS cssRules[0].cssText is "div { all: initial; }"
+PASS cssRules[1].cssText is not "div { all: initial; color: red; }"
+PASS contains(cssRules[1].cssText, "color: red;") is true
+PASS contains(cssRules[1].cssText, "background: initial;") is true
+PASS contains(cssRules[1].cssText, "direction: ") is false
+PASS contains(cssRules[1].cssText, "unicode-bidi: ") is false
+PASS cssRules[2].cssText is "div { all: initial; }"
+PASS cssRules[3].cssText is "div { all: initial !important; }"
+PASS cssRules[4].cssText is not "div { all: initial; color: red !important; }"
+PASS contains(cssRules[4].cssText, "color: red !important;") is true
+PASS contains(cssRules[4].cssText, "background: initial;") is true
+PASS contains(cssRules[4].cssText, "direction: ") is false
+PASS contains(cssRules[4].cssText, "unicode-bidi: ") is false
+PASS cssRules[5].cssText is "div { all: inherit; }"
+PASS cssRules[6].cssText is not "div { all: inherit; color: red; }"
+PASS contains(cssRules[6].cssText, "color: red;") is true
+PASS contains(cssRules[6].cssText, "direction: ") is false
+PASS contains(cssRules[6].cssText, "unicode-bidi: ") is false
+PASS cssRules[7].cssText is "div { all: inherit; }"
+PASS cssRules[8].cssText is "div { all: inherit !important; }"
+PASS cssRules[9].cssText is not "div { all: inherit; color: red !important; }"
+PASS contains(cssRules[9].cssText, "color: red !important") is true
+PASS contains(cssRules[9].cssText, "background: inherit;") is true
+PASS contains(cssRules[9].cssText, "direction: ") is false
+PASS contains(cssRules[9].cssText, "unicode-bidi: ") is false
+PASS cssRules[10].cssText is "div { }"
+PASS successfullyParsed is true
+
+TEST COMPLETE
+