Move screenshot capture to Java-side.

base/test/android/javatests/src/org/chromium/base/test/util/UrlUtils.java

Index: base/test/android/javatests/src/org/chromium/base/test/util/UrlUtils.java
diff --git a/base/test/android/javatests/src/org/chromium/base/test/util/UrlUtils.java b/base/test/android/javatests/src/org/chromium/base/test/util/UrlUtils.java
index 7433d8e0481076edab908f2e3ed3af4f9f3d9508..664eaa961acf45492efabce7a05326384b606032 100644
--- a/base/test/android/javatests/src/org/chromium/base/test/util/UrlUtils.java
+++ b/base/test/android/javatests/src/org/chromium/base/test/util/UrlUtils.java
@@ -41,6 +41,21 @@ public class UrlUtils {
     }
 
     /**
+     * Returns the root of the test data output directory.
+     */
+    public static String getTestFileOutputRoot() {
+        return PathUtils.getExternalStorageDirectory() + "/chromium_tests_output_root";
+    }
+
+    /**
+     * Construct the full path of a test data output file.
+     * @param path Pathname relative to external/
+     */
+    public static String getTestFileOutputPath(String path) {
+        return getTestFileOutputRoot() + "/" + path;
+    }
+
+    /**
      * Construct a suitable URL for loading a test data file.
      * @param path Pathname relative to external/chrome/test/data
      */