Disable DCHECKS.

These DCHECKs can be triggered during user touchscreen pinch, and are
blocking work in
https://chromium-review.googlesource.com/c/chromium/src/+/1286437/.
Temporarily disable them until we can handle GesturePinch events
properly.

Bug: 897216
Change-Id: I2a37c468133340a95ec2b3f580a966dd71451482
Reviewed-on: https://chromium-review.googlesource.com/c/1301567
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603105}

content/browser/renderer_host/render_widget_host_impl.cc

@@ -1293,12 +1293,16 @@ void RenderWidgetHostImpl::ForwardGestureEventWithLatencyInfo(
     // GSB and GSU events instead of sending them to the renderer and continues
     // to progress the fling. So, the renderer doesn't receive two GSB events
     // without any GSE in between.
-    DCHECK(!is_in_gesture_scroll_[gesture_event.SourceDevice()] ||
-           FlingCancellationIsDeferred());
+    // TODO(wjmaclean/mcnee): Restore the DCHECK below.
+    // https://crbug.com/897216
+    // DCHECK(!is_in_gesture_scroll_[gesture_event.SourceDevice()] ||
+    //        FlingCancellationIsDeferred());
     is_in_gesture_scroll_[gesture_event.SourceDevice()] = true;
   } else if (gesture_event.GetType() ==
              blink::WebInputEvent::kGestureScrollEnd) {
-    DCHECK(is_in_gesture_scroll_[gesture_event.SourceDevice()]);
+    // TODO(wjmaclean/mcnee): Restore the DCHECK below.
+    // https://crbug.com/897216
+    // DCHECK(is_in_gesture_scroll_[gesture_event.SourceDevice()]);
     is_in_gesture_scroll_[gesture_event.SourceDevice()] = false;
     is_in_touchpad_gesture_fling_ = false;
     if (view_)