swapContentViewCore is used by the Reader mode panel

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 41e3958ac6adbfd52c9aec1759dcf639b05b086e..5c0a27498c92959bf3818fe01da9f6c141a17b6a 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
@@ -2199,7 +2199,7 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
      * @param didFinishLoad Whether WebContentsObserver::DidFinishLoad() has
      *         already been called.
      */
-    protected void swapContentViewCore(ContentViewCore newContentViewCore,
+    public void swapContentViewCore(ContentViewCore newContentViewCore,

[David Trainor- moved to gerrit, 2015/05/19 17:37:23]

For API cleanliness sake, should this return the old ContentViewCore? 
Especially if we're not destroying the old native web contents...?

Just curious what people think.

[Ted C, 2015/05/19 17:52:06]

swapWebContents does not return the old webcontents, so I think it's ok to not
have it here until needed.

We also have the ability to getWebContents or getContentViewCore from the Tab
prior to calling this method, so I don't think it's a problem with this data
being unavailable.

[aruslan, 2015/05/19 18:36:51]

Agreed, getWebContents() prior to calling this method is sufficient if the
caller wants to control the lifetime of the old native web contents.

As to returning the old ContentViewCore, David's concern is valid, but on
different grounds: the method name is a confusing misnomer -- it couldn't
possibly return the old ContentViewCore because it destroys the one on the Tab.

I think it should have been named "replaceContentViewCore", but I leave this to
those in the know for a subsequent cross-repo method rename.

             boolean deleteOldNativeWebContents, boolean didStartLoad, boolean didFinishLoad) {
         int originalWidth = 0;
         int originalHeight = 0;