Expose VSync pausing through WindowAndroid and pause VSync during webVR presentation

ui/android/java/src/org/chromium/ui/base/WindowAndroid.java

Index: ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
diff --git a/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java b/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
index 882bb14deb693a3976aa16587107f750d30b6bf5..3f7e10a3724e00032528b11fd1765cc69a2f9c85 100644
--- a/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
+++ b/ui/android/java/src/org/chromium/ui/base/WindowAndroid.java
@@ -496,7 +496,7 @@ public class WindowAndroid {
     }
 
     @CalledByNative
-    private void requestVSyncUpdate() {
+    protected void requestVSyncUpdate() {
         mVSyncMonitor.requestUpdate();
     }
 
@@ -724,6 +724,11 @@ public class WindowAndroid {
         }
     }
 
+    protected void setVSyncPaused(boolean paused) {
+        if (mNativeWindowAndroid == 0) return;
+        nativeSetVSyncPaused(mNativeWindowAndroid, paused);
+    }
+
     private native long nativeInit(int displayId);
     private native void nativeOnVSync(long nativeWindowAndroid,
                                       long vsyncTimeMicros,
@@ -731,6 +736,7 @@ public class WindowAndroid {
     private native void nativeOnVisibilityChanged(long nativeWindowAndroid, boolean visible);
     private native void nativeOnActivityStopped(long nativeWindowAndroid);
     private native void nativeOnActivityStarted(long nativeWindowAndroid);
+    private native void nativeSetVSyncPaused(long nativeWindowAndroid, boolean paused);
     private native void nativeDestroy(long nativeWindowAndroid);
 
 }