base: Remove the string logging from CHECK().

content/browser/renderer_host/input/synthetic_gesture_target_base.cc

Index: content/browser/renderer_host/input/synthetic_gesture_target_base.cc
diff --git a/content/browser/renderer_host/input/synthetic_gesture_target_base.cc b/content/browser/renderer_host/input/synthetic_gesture_target_base.cc
index ae8f7e128e31a8123e389ea274bce728ec14900b..8aa239250310acd65be7aa7efc1c0adbf217b9ba 100644
--- a/content/browser/renderer_host/input/synthetic_gesture_target_base.cc
+++ b/content/browser/renderer_host/input/synthetic_gesture_target_base.cc
@@ -56,24 +56,24 @@ void SyntheticGestureTargetBase::DispatchInputEventToPlatform(
 
     // Check that all touch pointers are within the content bounds.
     for (unsigned i = 0; i < web_touch.touchesLength; i++)
+      // Touch coordinates are not within content bounds on TouchStart.
       CHECK(web_touch.touches[i].state != WebTouchPoint::StatePressed ||
             PointIsWithinContents(web_touch.touches[i].position.x,
-                                  web_touch.touches[i].position.y))
-          << "Touch coordinates are not within content bounds on TouchStart.";
+                                  web_touch.touches[i].position.y));
 
     DispatchWebTouchEventToPlatform(web_touch, latency_info);
   } else if (event.type == WebInputEvent::MouseWheel) {
     const WebMouseWheelEvent& web_wheel =
         static_cast<const WebMouseWheelEvent&>(event);
-    CHECK(PointIsWithinContents(web_wheel.x, web_wheel.y))
-        << "Mouse wheel position is not within content bounds.";
+    // Mouse wheel position is not within content bounds.
+    CHECK(PointIsWithinContents(web_wheel.x, web_wheel.y));
     DispatchWebMouseWheelEventToPlatform(web_wheel, latency_info);
   } else if (WebInputEvent::isMouseEventType(event.type)) {
     const WebMouseEvent& web_mouse =
         static_cast<const WebMouseEvent&>(event);
+    // Mouse pointer is not within content bounds on MouseDown.
     CHECK(event.type != WebInputEvent::MouseDown ||
-          PointIsWithinContents(web_mouse.x, web_mouse.y))
-        << "Mouse pointer is not within content bounds on MouseDown.";
+          PointIsWithinContents(web_mouse.x, web_mouse.y));
     DispatchWebMouseEventToPlatform(web_mouse, latency_info);
   } else {
     NOTREACHED();
@@ -86,7 +86,8 @@ void SyntheticGestureTargetBase::DispatchWebTouchEventToPlatform(
   // We assume that platforms supporting touch have their own implementation of
   // SyntheticGestureTarget to route the events through their respective input
   // stack.
-  CHECK(false) << "Touch events not supported for this browser.";
+  // Touch events not supported for this browser.
+  CHECK(false);
 }
 
 void SyntheticGestureTargetBase::DispatchWebMouseWheelEventToPlatform(