Tidy up usage of URLUtil constants

Several of these are duplicated; referring to a single source makes the code
paths using them easier to track down.
(also removing a spurious import)

Bug: 6237833

Change-Id: Ibdacc124c047e37c7f0ced9ecc6f26ae3e6b4326

core/java/android/webkit/BrowserFrame.java

@@ -692,13 +692,10 @@ private int getFile(String uri, byte[] buffer, int offset,
      * @return An InputStream to the android resource
      */
     private InputStream inputStreamForAndroidResource(String url) {
-        // This list needs to be kept in sync with the list in
-        // external/webkit/WebKit/android/WebCoreSupport/WebUrlLoaderClient.cpp
-        final String ANDROID_ASSET = "file:///android_asset/";
-        final String ANDROID_RESOURCE = "file:///android_res/";
-        final String ANDROID_CONTENT = "content:";
+        final String ANDROID_ASSET = URLUtil.ASSET_BASE;
+        final String ANDROID_RESOURCE = URLUtil.RESOURCE_BASE;
+        final String ANDROID_CONTENT = URLUtil.CONTENT_BASE;
 
-        // file:///android_res
         if (url.startsWith(ANDROID_RESOURCE)) {
             url = url.replaceFirst(ANDROID_RESOURCE, "");
             if (url == null || url.length() == 0) {
@@ -736,8 +733,6 @@ private InputStream inputStreamForAndroidResource(String url) {
                 Log.e(LOGTAG, "Exception: " + url);
                 return null;
             }
-
-        // file:///android_asset
         } else if (url.startsWith(ANDROID_ASSET)) {
             url = url.replaceFirst(ANDROID_ASSET, "");
             try {
@@ -747,8 +742,6 @@ private InputStream inputStreamForAndroidResource(String url) {
             } catch (IOException e) {
                 return null;
             }
-
-        // content://
         } else if (mSettings.getAllowContentAccess() &&
                    url.startsWith(ANDROID_CONTENT)) {
             try {

core/java/android/webkit/JniUtil.java

@@ -100,7 +100,7 @@ private static synchronized String getPackageName() {
         return sContext.getPackageName();
     }
 
-    private static final String ANDROID_CONTENT = "content:";
+    private static final String ANDROID_CONTENT = URLUtil.CONTENT_BASE;
 
     /**
      * Called by JNI. Calculates the size of an input stream by reading it.

core/java/android/webkit/MimeTypeMap.java

@@ -17,7 +17,6 @@
 package android.webkit;
 
 import android.text.TextUtils;
-import java.util.HashMap;
 import java.util.regex.Pattern;
 import libcore.net.MimeUtils;
 

core/java/android/webkit/URLUtil.java

@@ -38,6 +38,7 @@ public final class URLUtil {
     static final String RESOURCE_BASE = "file:///android_res/";
     static final String FILE_BASE = "file://";
     static final String PROXY_BASE = "file:///cookieless_proxy/";
+    static final String CONTENT_BASE = "content:";
 
     /**
      * Cleans up (if possible) user-entered web addresses
@@ -253,7 +254,7 @@ public static boolean isNetworkUrl(String url) {
      * @return True iff the url is a content: url.
      */
     public static boolean isContentUrl(String url) {
-        return (null != url) && url.startsWith("content:");
+        return (null != url) && url.startsWith(CONTENT_BASE);
     }
 
     /**