Remove all usage of -webkit-*gradient inside blink

The prefixed functions have been deprecated in 2011 and should
be use counted with the goal of removing them.

This patch just rewrites existing rules on top of the modern syntax:

-webkit-gradient(linear, top left, bottom left, from(white), to(black))

is equivalent to

linear-gradient(to bottom, white, black)

Review URL: https://codereview.chromium.org/152493003

git-svn-id: svn://svn.chromium.org/blink/trunk@166426 bbb929c8-8fbe-4397-9dbb-9b2b20218538
diff --git a/Source/core/css/html.css b/Source/core/css/html.css
index 86d7cbb..b92f4a3 100644
--- a/Source/core/css/html.css
+++ b/Source/core/css/html.css
@@ -915,7 +915,7 @@
 }
 
 meter::-webkit-meter-bar {
-    background: -webkit-gradient(linear, left top, left bottom, from(#ddd), to(#ddd), color-stop(0.20, #eee), color-stop(0.45, #ccc), color-stop(0.55, #ccc));
+    background: linear-gradient(to bottom, #ddd, #eee 20%, #ccc 45%, #ccc 55%, #ddd);
     height: 100%;
     width: 100%;
     -webkit-user-modify: read-only !important;
@@ -923,21 +923,21 @@
 }
 
 meter::-webkit-meter-optimum-value {
-    background: -webkit-gradient(linear, left top, left bottom, from(#ad7), to(#ad7), color-stop(0.20, #cea), color-stop(0.45, #7a3), color-stop(0.55, #7a3));
+    background: linear-gradient(to bottom, #ad7, #cea 20%, #7a3 45%, #7a3 55%, #ad7);
     height: 100%;
     -webkit-user-modify: read-only !important;
     box-sizing: border-box;
 }
 
 meter::-webkit-meter-suboptimum-value {
-    background: -webkit-gradient(linear, left top, left bottom, from(#fe7), to(#fe7), color-stop(0.20, #ffc), color-stop(0.45, #db3), color-stop(0.55, #db3));
+    background: linear-gradient(to bottom, #fe7, #ffc 20%, #db3 45%, #db3 55%, #fe7);
     height: 100%;
     -webkit-user-modify: read-only !important;
     box-sizing: border-box;
 }
 
 meter::-webkit-meter-even-less-good-value {
-    background: -webkit-gradient(linear, left top, left bottom, from(#f77), to(#f77), color-stop(0.20, #fcc), color-stop(0.45, #d44), color-stop(0.55, #d44));
+    background: linear-gradient(to bottom, #f77, #fcc 20%, #d44 45%, #d44 55%, #f77);
     height: 100%;
     -webkit-user-modify: read-only !important;
     box-sizing: border-box;