Prevent NPE in TextureView.getBitmap()

This crash could occur when invoking setSurfaceTexture() then getBitmap()
before the View has a chance to be drawn.

Change-Id: I25c55df15750e59b9c916e8f750de2c89718d39e

Author: Romain Guy

core/java/android/view/TextureView.java

@@ -561,7 +561,17 @@ public Bitmap getBitmap(Bitmap bitmap) {
             applyUpdate();
             applyTransformMatrix();
 
-            mLayer.copyInto(bitmap);
+            // This case can happen if the app invokes setSurfaceTexture() before
+            // we are able to create the hardware layer. We can safely initialize
+            // the layer here thanks to the validate() call at the beginning of
+            // this method
+            if (mLayer == null && mUpdateSurface) {
+                getHardwareLayer();
+            }
+
+            if (mLayer != null) {
+                mLayer.copyInto(bitmap);
+            }
         }
         return bitmap;
     }