Ensure we have an EGL context when building layers
Bug #5638421

This bug was introduced by the recent changes that force more frequent
flushes of the GL renderer.

Change-Id: I55dd4ace6ba1e70ab41927150d6c60c37d7fb196
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index e2f3919..39ec717 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -10140,7 +10140,11 @@
 
         switch (mLayerType) {
             case LAYER_TYPE_HARDWARE:
-                getHardwareLayer();
+                if (mAttachInfo.mHardwareRenderer != null &&
+                        mAttachInfo.mHardwareRenderer.isEnabled() &&
+                        mAttachInfo.mHardwareRenderer.validate()) {
+                    getHardwareLayer();
+                }
                 break;
             case LAYER_TYPE_SOFTWARE:
                 buildDrawingCache(true);