Expose SafeHtml.asString as a public member

Otherwise its nearly impossible to run Prettify against a safe
HTML string.

Change-Id: Ic7532c53d1bf43bd8685acf91a3c3bd9fc5782cd
Signed-off-by: Shawn O. Pearce <sop@google.com>
diff --git a/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtml.java b/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtml.java
index 8ab015e..5878ec0 100644
--- a/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtml.java
+++ b/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtml.java
@@ -264,5 +264,5 @@
   }
 
   /** @return a clean HTML string safe for inclusion in any context. */
-  abstract String asString();
+  public abstract String asString();
 }
diff --git a/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlBuilder.java b/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlBuilder.java
index a5d8484..9fe3267 100644
--- a/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlBuilder.java
+++ b/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlBuilder.java
@@ -361,7 +361,7 @@
   }
 
   @Override
-  String asString() {
+  public String asString() {
     return cb.toString();
   }
 
diff --git a/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlString.java b/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlString.java
index c037c6f..a229421 100644
--- a/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlString.java
+++ b/src/main/java/com/google/gwtexpui/safehtml/client/SafeHtmlString.java
@@ -22,7 +22,7 @@
   }
 
   @Override
-  String asString() {
+  public String asString() {
     return html;
   }
 }