Expose loading state from Blimp to Tab

chrome/android/java/src/org/chromium/chrome/browser/tab/TabBlimpContentsObserver.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tab/TabBlimpContentsObserver.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tab/TabBlimpContentsObserver.java b/chrome/android/java/src/org/chromium/chrome/browser/tab/TabBlimpContentsObserver.java
index 31bb061d1b9053ceb1a09a082fbd5c9302620750..93392269754bb877c865a10ee13cbcb0d2bffcc8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tab/TabBlimpContentsObserver.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tab/TabBlimpContentsObserver.java
@@ -6,6 +6,7 @@ package org.chromium.chrome.browser.tab;
 
 import org.chromium.base.ObserverList.RewindableIterator;
 import org.chromium.blimp_public.contents.BlimpContentsObserver;
+import org.chromium.ui.base.PageTransition;
 
 /**
  * BlimpContentsObserver used by Tab.
@@ -28,4 +29,14 @@ public class TabBlimpContentsObserver implements BlimpContentsObserver {
             observers.next().onUrlUpdated(mTab);
         }
     }
+
+    /**
+     * Tab can use this to drive what kind of content to show based on the URL.
+     */
+    @Override
+    public void onLoadingStateChanged(boolean loading) {
+        // TODO(dtrainor): Investigate if we need to pipe through a more accurate PageTransition
+        // here.
+        mTab.handleDidCommitProvisonalLoadForFrame(mTab.getUrl(), PageTransition.TYPED);
+    }
 }