Fix for issue 9659

Fix for issue 9659
Fixed already visible range check to use the proper width and height
Use max_y instead of max_x when calculating the new Y value for contents_
Commented code to (hopefully) make it easier to understand.

[tedoc2000, 2009-04-02 21:19:50]

Not sure who to give this to.

[tedoc2000, 2009-04-02 21:23:55]

Fixed a typo in the comment

[tedoc2000, 2009-04-02 21:29:09]

Sending to beng on jamesr's advice

[tedoc2000, 2009-04-03 00:05:17]

The comparison sign was wrong when calculating the new_x and new_y. Basically
when we scroll down or right (i.e. vis_rect.x() > x or vis_rect.y() > y) then we
want to set content's offsets to be our point - viewport's height and width.
Otherwise we can just use (x,y).

[tedoc2000, 2009-04-03 04:01:38]

Reassigning to sky based on issue 9659 assignment to sky

[sky, 2009-04-03 19:54:48]

http://codereview.chromium.org/60059/diff/2001/3001
File chrome/views/controls/scroll_view.cc (right):

http://codereview.chromium.org/60059/diff/2001/3001#newcode281
Line 281: // view
nit: add a '.' at the end of your sentence. 'farther over' is a bit awkward in
this context.

http://codereview.chromium.org/60059/diff/2001/3001#newcode288
Line 288: // (Range Check)
nit: 'with in' -> within. (Range Check) is a redundant.

http://codereview.chromium.org/60059/diff/2001/3001#newcode294
Line 294: // (Furthest right and down)
No need for furthest right and down here.

http://codereview.chromium.org/60059/diff/2001/3001#newcode317
Line 317: (vis_rect.y() > y) ? y : std::max(0, max_y - viewport_->height());
These should remain <, not >, otherwise you're aligning incorrectly. Consider
the following:

|
| vis y
|
|
| y

In this case vis y < y. We should make y the new origin, which means keeping
new_y at y, not max_y - viewport_->height().

[tedoc2000, 2009-04-03 21:07:07]

Fixed up comments

http://codereview.chromium.org/60059/diff/2001/3001
File chrome/views/controls/scroll_view.cc (right):

http://codereview.chromium.org/60059/diff/2001/3001#newcode317
Line 317: (vis_rect.y() > y) ? y : std::max(0, max_y - viewport_->height());
After discussion on IRC sky_ agreed my code was correct