fix web shard icons (#3251)

This is so all web tests show using the Chromium icon rather than OS icon.

Author: yjbanov

dashboard/lib/widgets/task_icon.dart

@@ -48,37 +48,41 @@ class TaskIcon extends StatelessWidget {
       );
     }
 
-    if (qualifiedTask.task!.toLowerCase().contains('_fuchsia')) {
+    final String matchedName = qualifiedTask.task!.toLowerCase();
+    final bool isWebTest = matchedName.contains('_web') || matchedName.contains('web_');
+    final bool isToolTest = matchedName.contains('_tool') || matchedName.contains('tool_');
+
+    if (matchedName.contains('_fuchsia')) {
       return Padding(
         padding: const EdgeInsets.all(2.0),
         child: Image.asset(
           'assets/fuchsia.png',
           color: blendFilter,
         ),
       );
-    } else if (qualifiedTask.task!.toLowerCase().contains('_web')) {
+    } else if (isWebTest && !isToolTest) {
       return Padding(
         padding: const EdgeInsets.all(2.0),
         child: Image.asset(
           'assets/chromium.png',
           color: blendFilter,
         ),
       );
-    } else if (qualifiedTask.task!.toLowerCase().contains('_android')) {
+    } else if (matchedName.contains('_android')) {
       return Icon(
         Icons.android,
         color: blendFilter,
       );
-    } else if (qualifiedTask.task!.toLowerCase().startsWith('linux')) {
+    } else if (matchedName.startsWith('linux')) {
       return Padding(
         padding: const EdgeInsets.all(2.0),
         child: Image.asset(
           'assets/linux.png',
           color: blendFilter,
         ),
       );
-    } else if (qualifiedTask.task!.toLowerCase().startsWith('mac')) {
-      if (qualifiedTask.task!.toLowerCase().contains('_ios')) {
+    } else if (matchedName.startsWith('mac')) {
+      if (matchedName.contains('_ios')) {
         return Icon(
           Icons.phone_iphone,
           color: blendFilter,
@@ -92,7 +96,7 @@ class TaskIcon extends StatelessWidget {
           ),
         );
       }
-    } else if (qualifiedTask.task!.toLowerCase().startsWith('win')) {
+    } else if (matchedName.startsWith('win')) {
       return Image.asset(
         'assets/windows.png',
         color: blendFilter,