[dartdevc] Adding custom prototype for MemoryInfo to accommodate Chrome API changes

Markzipan · commit-bot@chromium.org · commit e33f84d0812a · 2020-08-28T16:27:18.000Z
Chrome Canary no longer exposes window.performance.memory's constructor (it uses Object's instead). This hack lets (window.performance.memory is html.MemoryInfo) evaluate to true. See: #43193 Change-Id: I3c557467c3ea029052aba71f6695f4db0ec65515 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/160782 Reviewed-by: Sigmund Cherem <sigmund@google.com> Commit-Queue: Mark Zhou <markzipan@google.com>
diff --git a/sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/runtime.dart b/sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/runtime.dart
@@ -77,7 +77,8 @@ bool polyfill(window) => JS('', '''(() => {
     }
     if (typeof $window.MemoryInfo == "undefined") {
       if (typeof $window.performance.memory != "undefined") {
-        $window.MemoryInfo = $window.performance.memory.constructor;
+        $window.MemoryInfo = function () {};
+        $window.MemoryInfo.prototype = $window.performance.memory.__proto__;
       }
     }
     if (typeof $window.Geolocation == "undefined") {

Original file line number	Diff line number	Diff line change
`@@ -77,7 +77,8 @@ bool polyfill(window) => JS('', '''(() => {`
`77`	`77`	`}`
`78`	`78`	`if (typeof $window.MemoryInfo == "undefined") {`
`79`	`79`	`if (typeof $window.performance.memory != "undefined") {`
`80`		`- $window.MemoryInfo = $window.performance.memory.constructor;`
	`80`	`+ $window.MemoryInfo = function () {};`
	`81`	`+ $window.MemoryInfo.prototype = $window.performance.memory.__proto__;`
`81`	`82`	`}`
`82`	`83`	`}`
`83`	`84`	`if (typeof $window.Geolocation == "undefined") {`