Be more conservative about current buffer

Bug: 18065565
Change-Id: I0b9c85ecf384ebe525e3a38803ab77d7ee37f33a
diff --git a/libs/hwui/renderthread/EglManager.cpp b/libs/hwui/renderthread/EglManager.cpp
index 760fc15..e37aafc 100644
--- a/libs/hwui/renderthread/EglManager.cpp
+++ b/libs/hwui/renderthread/EglManager.cpp
@@ -105,11 +105,10 @@
 void EglManager::requireGlContext() {
     LOG_ALWAYS_FATAL_IF(mEglDisplay == EGL_NO_DISPLAY, "No EGL context");
 
-    // We don't care *WHAT* surface is active, just that one is active to give
-    // us access to the GL context
-    if (mCurrentSurface == EGL_NO_SURFACE) {
-        usePBufferSurface();
-    }
+    // We can't be certain about the state of the current surface (whether
+    // or not it is destroyed, for example), so err on the side of using
+    // the pbuffer surface which we fully control
+    usePBufferSurface();
 }
 
 void EglManager::loadConfig() {