Add support for ContentViewCore helpers on Tab

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
index 9246385f8588d6205b54339e37e350166fdcc358..34c3beec4b81aaacd4c60ac9bbe2a9ba8726dd6f 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
@@ -1353,6 +1353,17 @@ public class ContentViewCore
     }
 
     /**
+     * Sets whether or not this {@link ContentViewCore} will visibly display it's content. By
+     * default this is set to {@code true} so there is no need to call this to start showing content
+     * when initially creating a {@link ContentViewCore}.
+     * @param draws Whether or not this {@link ContentViewCore} should draw.
+     */
+    public void setDrawsContent(boolean draws) {
+        if (mNativeContentViewCore == 0) return;
+        nativeSetDrawsContent(mNativeContentViewCore, draws);
+    }
+
+    /**
      * To be called when the ContentView is shown.
      */
     public void onShow() {
@@ -3178,4 +3189,6 @@ public class ContentViewCore
             int x, int y, int w, int h);
 
     private native void nativeSetBackgroundOpaque(long nativeContentViewCoreImpl, boolean opaque);
+
+    private native void nativeSetDrawsContent(long nativeContentViewCoreImpl, boolean draws);
 }