Fix type errors in math.min() and math.max().

pkg/dev_compiler/tool/sdk_expected_errors.txt

Index: pkg/dev_compiler/tool/sdk_expected_errors.txt
diff --git a/pkg/dev_compiler/tool/sdk_expected_errors.txt b/pkg/dev_compiler/tool/sdk_expected_errors.txt
index a7b684df1b69626181c5ccccb446c759aa01b441..4237fa91c27dda0f2d96d788633f952420d8bf5d 100644
--- a/pkg/dev_compiler/tool/sdk_expected_errors.txt
+++ b/pkg/dev_compiler/tool/sdk_expected_errors.txt
@@ -21,10 +21,6 @@
 [error] Invalid override. The type of _StyleSheetList.[]= ((int, StyleSheet) → void) is not a subtype of JSMutableIndexable.[]= ((int, dynamic) → dynamic). (dart:html, line 38415, col 3)
 [error] Invalid override. The type of _EventStreamSubscription.asFuture (([dynamic]) → Future<dynamic>) is not a subtype of StreamSubscription<T>.asFuture (<E>([E]) → Future<E>). (dart:html, line 40152, col 3)
 [error] Invalid override. The type of JsArray.[]= ((Object, E) → void) is not a subtype of JsObject.[]= ((Object, dynamic) → dynamic). (dart:js, line 363, col 3)
-[error] The return type 'double' is not a 'T', as defined by the method 'min'. (dart:math, line 90, col 16)
-[error] The return type 'double' is not a 'T', as defined by the method 'min'. (dart:math, line 94, col 51)
-[error] The return type 'double' is not a 'T', as defined by the method 'max'. (dart:math, line 125, col 16)
-[error] The return type 'double' is not a 'T', as defined by the method 'max'. (dart:math, line 129, col 25)
 [warning] Unsound implicit cast from dynamic to List<String> (dart:_debugger, line 39, col 45)
 [warning] Unsound implicit cast from dynamic to List<NameValuePair> (dart:_debugger, line 750, col 43)
 [warning] Unsound implicit cast from dynamic to List<String> (dart:_isolate_helper, line 839, col 37)