Updated links to Material design guidelines to use short links. (#17077)

examples/catalog/lib/app_bar_bottom.dart

@@ -141,5 +141,5 @@ Sample: AppBarBottomSample
 
 See also:
   - The "Components-Tabs" section of the material design specification:
-    <https://material.io/guidelines/components/tabs.html>
+    <https://material.io/go/design-tabs>
 */

examples/catalog/lib/tabbed_app_bar.dart

@@ -98,5 +98,5 @@ Sample: TabbedAppBarSample
 
 See also:
   - The "Components-Tabs" section of the material design specification:
-    <https://material.io/guidelines/components/tabs.html>
+    <https://material.io/go/design-tabs>
 */

packages/flutter/lib/src/material/colors.dart

@@ -66,7 +66,7 @@ class MaterialColor extends ColorSwatch<int> {
 /// See also:
 ///
 ///  * [Colors], which defines all of the standard material colors.
-///  * <https://material.io/guidelines/style/color.html#color-color-schemes>
+///  * <https://material.io/go/design-theming#color-color-schemes>
 class MaterialAccentColor extends ColorSwatch<int> {
   /// Creates a color swatch with a variety of shades appropriate for accent
   /// colors.

packages/flutter/lib/src/material/material_localizations.dart

@@ -180,7 +180,7 @@ abstract class MaterialLocalizations {
   /// obtained from [Theme.of] no longer inherits text style properties and
   /// contains a complete set of properties needed to style a [Text] widget.
   ///
-  /// See also: https://material.io/guidelines/style/typography.html
+  /// See also: https://material.io/go/design-typography
   TextTheme get localTextGeometry;
 
   /// Formats [number] as a decimal, inserting locale-appropriate thousands

packages/flutter/lib/src/material/paginated_data_table.dart

@@ -31,7 +31,7 @@ import 'theme.dart';
 /// See also:
 ///
 ///  * [DataTable], which is not paginated.
-///  * <https://material.io/guidelines/components/data-tables.html#data-tables-tables-within-cards>
+///  * <https://material.io/go/design-data-tables#data-tables-tables-within-cards>
 class PaginatedDataTable extends StatefulWidget {
   /// Creates a widget describing a paginated [DataTable] on a [Card].
   ///

packages/flutter/lib/src/material/theme_data.dart

@@ -624,7 +624,7 @@ class ThemeData extends Diagnosticable {
     // more towards using light text than WCAG20 recommends. Material Design spec
     // doesn't say what value to use, but 0.15 seemed close to what the Material
     // Design spec shows for its color palette on
-    // <https://material.io/guidelines/style/color.html#color-color-palette>.
+    // <https://material.io/go/design-theming#color-color-palette>.
     const double kThreshold = 0.15;
     if ((relativeLuminance + 0.05) * (relativeLuminance + 0.05) > kThreshold)
       return Brightness.light;

packages/flutter/lib/src/material/typography.dart

@@ -17,7 +17,7 @@ import 'colors.dart';
 /// [BuildContext] and read the [ThemeData.textTheme] property.
 ///
 /// The following image [from the material design
-/// specification](https://material.io/guidelines/style/typography.html#typography-styles)
+/// specification](https://material.io/go/design-typography#typography-styles)
 /// shows the recommended styles for each of the properties of a [TextTheme].
 /// This image uses the `Roboto` font, which is the font used on Android. On
 /// iOS, the [San Francisco
@@ -435,8 +435,8 @@ class Typography {
 /// expected to use [Theme.of] to get [TextTheme] objects fully populated with
 /// font properties.
 ///
-/// See also: https://material.io/guidelines/style/typography.html
-// TODO(yjbanov): implement font fallback (see "Font stack" at https://material.io/guidelines/style/typography.html)
+/// See also: https://material.io/go/design-typography
+// TODO(yjbanov): implement font fallback (see "Font stack" at https://material.io/go/design-typography)
 class _MaterialTextColorThemes {
   static const TextTheme blackMountainView = const TextTheme(
     display4: const TextStyle(debugLabel: 'blackMountainView display4', fontFamily: 'Roboto',         inherit: true, color: Colors.black54, decoration: TextDecoration.none),
@@ -496,7 +496,7 @@ class _MaterialTextColorThemes {
 }
 
 /// Defines text geometries for the three language categories defined in
-/// https://material.io/guidelines/style/typography.html.
+/// https://material.io/go/design-typography.
 class MaterialTextGeometry {
   /// The name of the English-like script category.
   static const String englishLikeCategory = 'English-like';

packages/flutter/test/material/list_tile_test.dart

@@ -46,7 +46,7 @@ class TestTextState extends State<TestText> {
 
 void main() {
   testWidgets('ListTile geometry (LTR)', (WidgetTester tester) async {
-    // See https://material.io/guidelines/components/lists.html
+    // See https://material.io/go/design-lists
 
     final Key leadingKey = new GlobalKey();
     final Key trailingKey = new GlobalKey();

packages/flutter/test/material/text_field_test.dart

@@ -1168,7 +1168,7 @@ void main() {
       ),
     );
     final double iconRight = tester.getTopRight(find.byType(Icon)).dx;
-    // Per https://material.io/guidelines/components/text-fields.html#text-fields-layout
+    // Per https://material.io/go/design-text-fields#text-fields-layout
     // There's a 16 dps gap between the right edge of the icon and the text field's
     // container, and the 12dps more padding between the left edge of the container
     // and the left edge of the input and label.

packages/flutter_localizations/lib/src/l10n/README.md

@@ -135,7 +135,7 @@ a string that matches one of the formats defined by
 https://docs.flutter.io/flutter/material/TimeOfDayFormat-class.html.
 
 The value of `scriptCategory` is based on the
-[Language categories reference](https://material.io/guidelines/style/typography.html#typography-language-categories-reference)
+[Language categories reference](https://material.io/go/design-typography#typography-language-categories-reference)
 section in the Material spec. The `scriptCategory` value is used when looking up
 the `TextTheme`, see the
 [MaterialTextGeometry](https://docs.flutter.io/flutter/material/MaterialTextGeometry/forScriptCategory.html)

packages/flutter_localizations/lib/src/l10n/material_en.arb

 {
   "scriptCategory": "English-like",
   "@scriptCategory": {
-    "description": "The name of the language's script category (see https://material.io/guidelines/style/typography.html#typography-language-categories-reference)."
+    "description": "The name of the language's script category (see https://material.io/go/design-typography#typography-language-categories-reference)."
   },
 
   "timeOfDayFormat": "h:mm a",