[Android] Move LoadUrl from Tab upstream.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java b/chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java
index ad96d031ef5bee2f6d9f6047bfbb10938efeecc7..f8df8e64eb4b953570f84fcc63c063f3f84776f4 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java
@@ -26,6 +26,19 @@ public interface TabObserver {
     void onContentChanged(Tab tab);
 
     /**
+     * Called when loadUrl is triggered on a a {@link Tab}.
+     * @param tab      The notifying {@link Tab}.
+     * @param url      The url that is being loaded.
+     * @param loadType The type of load that was performed.
+     *
+     * @see TabLoadStatus#PAGE_LOAD_FAILED
+     * @see TabLoadStatus#DEFAULT_PAGE_LOAD
+     * @see TabLoadStatus#PARTIAL_PRERENDERED_PAGE_LOAD
+     * @see TabLoadStatus#FULL_PRERENDERED_PAGE_LOAD
+     */
+    void onLoadUrl(Tab tab, String url, int loadType);
+
+    /**
      * Called when the favicon of a {@link Tab} has been updated.
      * @param tab The notifying {@link Tab}.
      */