Thanks for reporting.  It's a valid suggestion and use case.

Would adding a "getBounds" method to the Polyline/Polygon object suffice?

getBounds would suffice in most cases, but the problem is that Bounds are
rectangular, and geografic regions rearly are rectangular and therefore would the
getBounds method crudly tell whether a point is in the polygon or not. 

Is there a more precise method to determine this?

getBounds would actually suffice.

V2 equivalent methon of Point in Polygon: 
// Create polygon method for collision detection
GPolygon.prototype.containsLatLng = function(latLng) {
    // Do simple calculation so we don't do more CPU-intensive calcs for obvious misses
    var bounds = this.getBounds();
   
    if(!bounds.containsLatLng(latLng)) {
        return false;
    }
   
    var numPoints = this.getVertexCount();
    var inPoly = false;
    var i;
    var j = numPoints-1;
   
    for(var i=0; i < numPoints; i++) {
        var vertex1 = this.getVertex(i);
        var vertex2 = this.getVertex(j);
       
        if (vertex1.lng() < latLng.lng() && vertex2.lng() >= latLng.lng() ||
vertex2.lng() < latLng.lng() && vertex1.lng() >= latLng.lng())  {
            if (vertex1.lat() + (latLng.lng() - vertex1.lng()) / (vertex2.lng() -
vertex1.lng()) * (vertex2.lat() - vertex1.lat()) < latLng.lat()) {
                inPoly = !inPoly;
            }
        }
       
        j = i;
    }
   
    return inPoly;
};

Okay, thanks for confirming.

I've shared your request to add a getBounds method to both Polyline and Polygon objects.

Hanif, instead of adding a getBounds method, you can construct your own LatLngBounds
by using the extend() method against your Polyline/Polygon paths.  Then you can call
LatLngBounds.contains() to determine whether a point exists within.

Would that affect the performance? It would have to iterate throu all of the points
in the polygon, or would the getBounds() method have the same logic and performance?

A getBounds() method would essentially be doing the same thing.

Are you trying to determine if a point exists within an enclosed polyline or polygon?
 Reason I ask is because LatLngBounds are always in the shape of a rectangle.  If
you're trying to determine whether a point exists within a triangular polygon, using
LatLngBounds would not work correctly since the rectangular shape would include areas
outside the shape.

(No comment was entered for this change.)

The answer to the last question would slightly modify this feature request to be more
specific.  For example, a more descriptive function name for the proposed
functionality would be Polygon.isLatLngInside or Polyline.isLatLngNear or something
of the sort.

(No comment was entered for this change.)

(No comment was entered for this change.)

(No comment was entered for this change.)

If you can't wait for Google solution, here is mine:

if (!google.maps.Polyline.prototype.getBounds)
google.maps.Polyline.prototype.getBounds = function() {

  var path = this.getPath();
  
  var slat, blat = path.getAt(0).lat();
  var slng, blng = path.getAt(0).lng();

  for (var i = 1; i < path.getLength(); i++) {
    var e = path.getAt(i);
    slat = ((slat < e.lat())?slat:e.lat());
    blat = ((blat > e.lat())?blat:e.lat());
    slng = ((slng < e.lng())?slng:e.lng());
    blng = ((blng > e.lng())?blng:e.lng());
  }      

  return new google.maps.LatLngBounds(new google.maps.LatLng(slat, slng), new google.maps.LatLng(blat, blng));
  
}

Simplier version:

if (!google.maps.Polyline.prototype.getBounds)
google.maps.Polyline.prototype.getBounds = function() {
  
  var bounds = new google.maps.LatLngBounds();
   
  this.getPath().forEach( function(latlng) { bounds.extend(latlng); } ); 
  
  return bounds; 
  
}

(No comment was entered for this change.)

(No comment was entered for this change.)

(No comment was entered for this change.)

 Issue 2451  has been merged into this issue.

(No comment was entered for this change.)