Fix disk read violation when create GvrLayout

BUG=672477

Review-Url: https://codereview.chromium.org/2556253006
Cr-Commit-Position: refs/heads/master@{#437561}

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/NonPresentingGvrContextImpl.java

@@ -5,17 +5,13 @@
 package org.chromium.chrome.browser.vr_shell;
 
 import android.app.Activity;
-import android.os.StrictMode;
 
 import com.google.vr.ndk.base.GvrLayout;
 
-import org.chromium.base.Log;
-
 /**
  * Creates an active GvrContext from a detached GvrLayout. This is used by magic window mode.
  */
 public class NonPresentingGvrContextImpl implements NonPresentingGvrContext {
-    private static final String TAG = "NPGvrContextImpl";
     private GvrLayout mGvrLayout;
 
     public NonPresentingGvrContextImpl(Activity activity) {
@@ -24,17 +20,7 @@ public class NonPresentingGvrContextImpl implements NonPresentingGvrContext {
 
     @Override
     public long getNativeGvrContext() {
-        long nativeGvrContext = 0;
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-        try {
-            nativeGvrContext = mGvrLayout.getGvrApi().getNativeGvrContext();
-        } catch (Exception ex) {
-            Log.e(TAG, "Unable to instantiate GvrApi", ex);
-            return 0;
-        } finally {
-            StrictMode.setThreadPolicy(oldPolicy);
-        }
-        return nativeGvrContext;
+        return mGvrLayout.getGvrApi().getNativeGvrContext();
     }
 
     @Override

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilderImpl.java

@@ -5,7 +5,9 @@
 package org.chromium.chrome.browser.vr_shell;
 
 import android.app.Activity;
+import android.os.StrictMode;
 
+import org.chromium.base.Log;
 import org.chromium.base.annotations.UsedByReflection;
 
 /**
@@ -14,6 +16,7 @@ import org.chromium.base.annotations.UsedByReflection;
  */
 @UsedByReflection("VrShellDelegate.java")
 public class VrClassesBuilderImpl implements VrClassesBuilder {
+    private static final String TAG = "VrClassesBuilderImpl";
     private final Activity mActivity;
 
     @UsedByReflection("VrShellDelegate.java")
@@ -23,12 +26,28 @@ public class VrClassesBuilderImpl implements VrClassesBuilder {
 
     @Override
     public NonPresentingGvrContext createNonPresentingGvrContext() {
-        return new NonPresentingGvrContextImpl(mActivity);
+        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+        try {
+            return new NonPresentingGvrContextImpl(mActivity);
+        } catch (Exception ex) {
+            Log.e(TAG, "Unable to instantiate NonPresentingGvrContextImpl", ex);
+            return null;
+        } finally {
+            StrictMode.setThreadPolicy(oldPolicy);
+        }
     }
 
     @Override
     public VrShell createVrShell() {
-        return new VrShellImpl(mActivity);
+        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+        try {
+            return new VrShellImpl(mActivity);
+        } catch (Exception ex) {
+            Log.e(TAG, "Unable to instantiate VrShellImpl", ex);
+            return null;
+        } finally {
+            StrictMode.setThreadPolicy(oldPolicy);
+        }
     }
 
     @Override

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java

@@ -410,6 +410,7 @@ public class VrShellDelegate {
     private long createNonPresentingNativeContext() {
         if (mVrClassesBuilder == null) return 0;
         mNonPresentingGvrContext = mVrClassesBuilder.createNonPresentingGvrContext();
+        if (mNonPresentingGvrContext == null) return 0;
         return mNonPresentingGvrContext.getNativeGvrContext();
     }
 
@@ -473,11 +474,8 @@ public class VrShellDelegate {
 
     private boolean createVrShell() {
         if (mVrClassesBuilder == null) return false;
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-        StrictMode.allowThreadDiskWrites();
         mVrShell = mVrClassesBuilder.createVrShell();
-        StrictMode.setThreadPolicy(oldPolicy);
-        return true;
+        return mVrShell != null;
     }
 
     private void addVrViews() {