Fix infobar scrolling.

The infobar container became non-scrollable because InfoBarContainer now
ignores all touch events in InfoBarContainer.onTouch(). These touch
events need to be swallowed to prevent them from reaching the webpage,
but they should be swallowed in ContentWrapperView, not in
InfoBarContainer, so that InfoBarContainer (which extends ScrollView)
can be scrolled.

The offending CL: https://codereview.chromium.org/824763002

BUG=453103

Review URL: https://codereview.chromium.org/872113003

Cr-Commit-Position: refs/heads/master@{#313668}

chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarContainer.java

@@ -188,6 +188,7 @@ public class InfoBarContainer extends ScrollView {
 
     @Override
     public boolean onTouchEvent(MotionEvent event) {
+        super.onTouchEvent(event);
         // Consume all touch events so they do not reach the ContentView.
         return true;
     }