Implementation of GetFavicon for current tab.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/Tab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/Tab.java b/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
index 4db0aa3208985edfc3e3d9c09925f9e074588cca..bb861e1fd0c9c4b086467705e2f1e75fc6d78560 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
@@ -139,6 +139,10 @@ public class Tab implements NavigationClient {
 
     private boolean mIsClosing = false;
 
+    private Bitmap mFavicon = null;
+
+    private String mFaviconUrl = null;
+
     /**
      * A default {@link ChromeContextMenuItemDelegate} that supports some of the context menu
      * functionality.
@@ -885,10 +889,9 @@ public class Tab implements NavigationClient {
     /**
      * @return The bitmap of the favicon scaled to 16x16dp. null if no favicon
      *         is specified or it requires the default favicon.
-     *         TODO(bauerb): Upstream implementation.
      */
     public Bitmap getFavicon() {
-        return null;
+        return mFavicon;
     }
 
     /**
@@ -1014,7 +1017,15 @@ public class Tab implements NavigationClient {
      */
     @CalledByNative
     protected void onFaviconUpdated() {
-        for (TabObserver observer : mObservers) observer.onFaviconUpdated(this);
+        if (mContentViewCore != null) {
+            if ((mFaviconUrl == null) || (!mFaviconUrl.equals(mContentViewCore.getUrl()))) {

[David Trainor- moved to gerrit, 2014/07/21 18:18:17]

Could this change on a page refresh (even if the URL stays the same)?  Also if
nobody cares about the favicon we shouldn't bother building it.  Maybe we should
do something like:

onFaviconUpdated:
mFavicon = null;
mFaviconUrl = null;

getFavicon:
if (mFavicon == null || !cvcurl.equals(faviconurl)) buildFavicon;
return mFavicon;

[Jitu( very slow this week), 2014/07/24 14:08:21]

Changes done as per suggestion

+                if (mNativeTabAndroid == 0)
+                    return;
+                mFavicon = nativeGetFavicon(mNativeTabAndroid);
+                mFaviconUrl = mContentViewCore.getUrl();
+                for (TabObserver observer : mObservers) observer.onFaviconUpdated(this);
+            }
+        }
     }
 
     /**
@@ -1156,4 +1167,5 @@ public class Tab implements NavigationClient {
     private native void nativeSetActiveNavigationEntryTitleForUrl(long nativeTabAndroid, String url,
             String title);
     private native boolean nativePrint(long nativeTabAndroid);
+    private native Bitmap nativeGetFavicon(long nativeTabAndroid);
 }