Fix VR text selection test flakiness

Fixes the VrBrowserWebInputEditingTest#testTextSelection flakiness on
Nougat devices (for real this time) by further decreasing the rate at
which clicks are sent to the content node.

TBR=billorr@chromium.org

Bug: 953990
Change-Id: I016b3dc845df4d6c7fd461688a222bc16f4e4c7e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1634724Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664484}

chrome/android/javatests/src/org/chromium/chrome/browser/vr/util/NativeUiUtils.java

@@ -220,10 +220,10 @@ public class NativeUiUtils {
                 clickElement(UserFriendlyElementName.CONTENT_QUAD, clickCoordinates);
                 // Rarely, sending clicks back to back can cause the web contents to miss a click.
                 // So, if we're going to be sending more, introduce a few input-less frames to avoid
-                // this issue. 3 appears to currently be the magic number that lets the web contents
+                // this issue. 5 appears to currently be the magic number that lets the web contents
                 // reliably pick up all clicks.
                 if (i < numClicks - 1) {
-                    for (int j = 0; j < 3; ++j) {
+                    for (int j = 0; j < 5; ++j) {
                         hoverElement(UserFriendlyElementName.CONTENT_QUAD, clickCoordinates);
                     }
                 }