Fix size estimation for prerender in custom tabs

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTab.java b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTab.java
index b40f9a4e465faae371ed8aad320d362e60182729..baa2c952862de2346bc6218ffe9f469ce17fb1c8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTab.java
@@ -7,6 +7,7 @@ package org.chromium.chrome.browser.customtabs;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.ResolveInfo;
+import android.graphics.Point;
 import android.graphics.Rect;
 import android.os.IBinder;
 import android.os.SystemClock;
@@ -154,6 +155,7 @@ public class CustomTab extends ChromeTab {
     private CustomTabObserver mTabObserver;
     private final boolean mEnableUrlBarHiding;
     private boolean mShouldReplaceCurrentEntry;
+    private Point mPrerenderedSize = new Point();
 
     /**
      * Construct an CustomTab. Note that url and referrer given here is only used to retrieve a
@@ -167,11 +169,13 @@ public class CustomTab extends ChromeTab {
         mEnableUrlBarHiding = enableUrlBarHiding;
         CustomTabsConnection customTabsConnection =
                 CustomTabsConnection.getInstance(activity.getApplication());
-        WebContents webContents = customTabsConnection.takePrerenderedUrl(session, url, referrer);
+        WebContents webContents = customTabsConnection.takePrerenderedUrl(
+                session, url, referrer, mPrerenderedSize);
         if (webContents == null) {
             webContents = customTabsConnection.takeSpareWebContents();
             // TODO(lizeb): Remove this once crbug.com/521729 is fixed.
             if (webContents != null) mShouldReplaceCurrentEntry = true;
+            mPrerenderedSize = null;
         }
         if (webContents == null) {
             webContents = WebContentsFactory.createWebContents(isIncognito(), false);
@@ -182,6 +186,14 @@ public class CustomTab extends ChromeTab {
         addObserver(mTabObserver);
     }
 
+    @Override
+    protected void initContentViewCore(WebContents webContents) {
+        super.initContentViewCore(webContents);
+        if (mPrerenderedSize != null) {
+            getContentViewCore().onSizeChanged(mPrerenderedSize.x, mPrerenderedSize.y, 0, 0);
+        }
+    }
+
     /**
      * Loads a URL and tracks its load time, from the timestamp of the intent arrival.
      *