[Android] Add a check function for intent fallback navigation

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

Index: chrome/android/java/src/org/chromium/chrome/browser/UrlUtilities.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/UrlUtilities.java b/chrome/android/java/src/org/chromium/chrome/browser/UrlUtilities.java
index 4ae65c0df987881a8e9d8e84fc857ea00a04b0f6..ce2ad72d06c59ea5673cccdea198a8107fd86385 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/UrlUtilities.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/UrlUtilities.java
@@ -37,6 +37,12 @@ public class UrlUtilities {
             "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.
      *
      * @return True if the URI's scheme is one that ContentView can handle.
@@ -61,6 +67,28 @@ 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) {

[palmer, 2014/12/09 22:04:26]

Arguably, *this* method's caller should do new URI(...). In general, my
inclination is to push strong typing up and up and up to higher layers of the
API.

But as written this is not wrong, so my comment is just a nit.

+        try {
+            return isValidForIntentFallbackNavigation(new URI(uri));
+        } catch (URISyntaxException e) {
+            return false;
+        }
+    }
+
+    /**
+     * @param uri A URI.
+     *
      * @return True if the URI's scheme is one that Chrome can download.
      */
     public static boolean isDownloadableScheme(URI uri) {