WebVR: avoid race conditions for partially-initialized display

chrome/browser/android/vr_shell/vr_shell_delegate.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/vr_shell/vr_shell_delegate.h"
 
 #include "base/android/jni_android.h"
 #include "chrome/browser/android/vr_shell/vr_shell.h"
 #include "device/vr/android/gvr/gvr_device_provider.h"
 #include "jni/VrShellDelegate_jni.h"
@@ skipping 15 matching lines @@
 
   // GvrDelegate implementation
   void SetWebVRSecureOrigin(bool secure_origin) override {}
   void SubmitWebVRFrame() override {}
   void UpdateWebVRTextureBounds(const gvr::Rectf& left_bounds,
                                 const gvr::Rectf& right_bounds) override {}
   void SetGvrPoseForWebVr(const gvr::Mat4f& pose,
                           uint32_t pose_index) override {}
   void SetWebVRRenderSurfaceSize(int width, int height) override {}
   gvr::Sizei GetWebVRCompositorSurfaceSize() override {
-    return device::kFallbackRenderTargetSize; }
+    return device::kInvalidRenderTargetSize; }
   gvr::GvrApi* gvr_api() override { return gvr_api_.get(); }
   base::WeakPtr<GvrNonPresentingDelegate> GetWeakPtr() {
     return weak_ptr_factory_.GetWeakPtr();
   }
  private:
   std::unique_ptr<gvr::GvrApi> gvr_api_;
   base::WeakPtrFactory<GvrNonPresentingDelegate> weak_ptr_factory_;
 };
 
 VrShellDelegate::VrShellDelegate(JNIEnv* env, jobject obj)
@@ skipping 92 matching lines @@
 
 bool RegisterVrShellDelegate(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 jlong Init(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   return reinterpret_cast<intptr_t>(new VrShellDelegate(env, obj));
 }
 
 }  // namespace vr_shell