[Android] Add a check function for intent fallback navigation

BUG=440178

Review URL: https://codereview.chromium.org/785163002

Cr-Commit-Position: refs/heads/master@{#308480}

chrome/android/java/src/org/chromium/chrome/browser/UrlUtilities.java

@@ -36,6 +36,12 @@ public class UrlUtilities {
     private static final HashSet<String> INTERNAL_SCHEMES = CollectionUtil.newHashSet(
             "chrome", "chrome-native", "about");
 
+    /**
+     * URI schemes that can be handled in Intent fallback navigation.
+     */
+    private static final HashSet<String> FALLBACK_VALID_SCHEMES = CollectionUtil.newHashSet(
+            "http", "https");
+
     /**
      * @param uri A URI.
      *
@@ -58,6 +64,28 @@ public class UrlUtilities {
         }
     }
 
+    /**
+     * @param uri A URI.
+     *
+     * @return True if the URI is valid for Intent fallback navigation.
+     */
+    public static boolean isValidForIntentFallbackNavigation(URI uri) {
+        return FALLBACK_VALID_SCHEMES.contains(uri.getScheme());
+    }
+
+    /**
+     * @param uri A URI.
+     *
+     * @return True if the URI is valid for Intent fallback navigation.
+     */
+    public static boolean isValidForIntentFallbackNavigation(String uri) {
+        try {
+            return isValidForIntentFallbackNavigation(new URI(uri));
+        } catch (URISyntaxException e) {
+            return false;
+        }
+    }
+
     /**
      * @param uri A URI.
      *

chrome/android/javatests/src/org/chromium/chrome/browser/UrlUtilitiesTest.java

@@ -61,6 +61,16 @@ public class UrlUtilitiesTest extends InstrumentationTestCase {
         assertFalse(UrlUtilities.isDownloadableScheme("ht\ntp://awesome.example.com/"));
     }
 
+    @SmallTest
+    public void testIsValidForIntentFallbackUrl() {
+        assertTrue(UrlUtilities.isValidForIntentFallbackNavigation(
+                "https://user:pass@:awesome.com:9000/bad-scheme:#fake:"));
+        assertTrue(UrlUtilities.isValidForIntentFallbackNavigation("http://awesome.example.com/"));
+        assertFalse(UrlUtilities.isValidForIntentFallbackNavigation("inline:skates.co.uk"));
+        assertFalse(UrlUtilities.isValidForIntentFallbackNavigation("javascript:alert(1)"));
+        assertFalse(UrlUtilities.isValidForIntentFallbackNavigation(""));
+    }
+
     @SmallTest
     public void testFixUrl() throws URISyntaxException {
         try {