Add logic to parse "data:" URLs to RoundedIconGenerator.java

BUG=505430

Review URL: https://codereview.chromium.org/1245233002

Cr-Commit-Position: refs/heads/master@{#339769}

chrome/android/java/src/org/chromium/chrome/browser/widget/RoundedIconGenerator.java

@@ -187,6 +187,6 @@ public class RoundedIconGenerator {
             Log.w(TAG, "Unable to parse the URL for generating an icon: " + url);
         }
 
-        return null;
+        return url;
     }
 }

chrome/android/javatests/src/org/chromium/chrome/browser/widget/RoundedIconGeneratorTest.java

@@ -49,7 +49,9 @@ public class RoundedIconGeneratorTest extends NativeLibraryTestBase {
         assertEquals("google-chrome", getIconTextForUrl("https://google-chrome/", false));
         assertEquals("127.0.0.1", getIconTextForUrl("http://127.0.0.1/", false));
 
-        // Verify that file:// URLs will still return NULL.
-        assertNull(getIconTextForUrl("file:///home/chrome/test.html", false));
+        // Verify that the fallback is the the URL itself.
+        assertEquals("file:///home/chrome/test.html",
+                getIconTextForUrl("file:///home/chrome/test.html", false));
+        assertEquals("data:image", getIconTextForUrl("data:image", false));
     }
 }