Core: Drop support for Edge Legacy (i.e. non-Chromium Microsoft Edge)

Drop support for Edge Legacy: the non-Chromium, EdgeHTML-based Microsoft
Edge version. Also, restrict some workarounds that were applied
unconditionally in all browsers to run only in IE now. This slightly
increases the size but reduces the performance burden on modern browsers
that don't need the workarounds.

Also, clean up some comments & remove some obsolete workarounds.

Fixes gh-4568
Closes gh-4792

1 files changed, 7 insertions, 28 deletions

diff --git a/test/unit/support.js b/test/unit/support.js
index b2d4eb350..008453085 100644
--- a/test/unit/support.js
+++ b/test/unit/support.js
@@ -58,39 +58,18 @@ testIframe(
 	var expected,
 		userAgent = window.navigator.userAgent,
 		expectedMap = {
-			edge: {
-				reliableTrDimensions: false,
-				scope: undefined
-			},
-			ie_11: {
-				reliableTrDimensions: false,
-				scope: undefined
-			},
-			chrome: {
-				reliableTrDimensions: true,
-				scope: true
-			},
-			safari: {
-				reliableTrDimensions: true,
-				scope: true
-			},
-			firefox: {
-				reliableTrDimensions: true,
-				scope: true
-			},
-			ios: {
-				reliableTrDimensions: true,
-				scope: true
-			}
+			ie_11: {},
+			chrome: {},
+			safari: {},
+			firefox: {},
+			ios: {}
 		};
 
-	if ( /edge\//i.test( userAgent ) ) {
-		expected = expectedMap.edge;
-	} else if ( document.documentMode ) {
+	if ( document.documentMode ) {
 		expected = expectedMap.ie_11;
 	} else if ( /chrome/i.test( userAgent ) ) {
 
-		// Catches Chrome on Android & Opera as well.
+		// Catches Edge, Chrome on Android & Opera as well.
 		expected = expectedMap.chrome;
 	} else if ( /\b\d+(\.\d+)+ safari/i.test( userAgent ) ) {
 		expected = expectedMap.safari;