Fixed tab dragging which was broken on high DPI windows for scales other than 100%.

Fixed tab dragging which was broken on high DPI windows for scales other than 100%.

The tab dragging code uses the GetCursorPos API to determine the tab strip to be used
to drag the tab into. This API returns values in pixel. We need to convert to DIP and
vice versa wherever needed.

Changes as below:-
1. window_finder_win.cc :- The cursor position after my changes now comes in as DIP.
                           We need to convert to pixel as this class uses PtInRect
                           and other APIs which need values in pixel.
2. screen_win.cc :- The GetCursorScreenPoint now returns values in DIP which is what is
                    expected. These values are passed to views and other places which
                    expect values in DIP.
3. apps_grid_view.cc :- Converted cursor position to DIP before passing it to the views code.

Looked at other usages of this API. They seem to be in order. Thought about adding helpers for
this for Windows. Decided against it as it is very hard to enforce given that it is a popular
API.

BUG=364969
R=sky@chromium.org, sky

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266744

[sky, 2014-04-28 13:44:48]

https://codereview.chromium.org/256923002/diff/1/chrome/browser/ui/views/tabs...
File chrome/browser/ui/views/tabs/window_finder_win.cc (right):

https://codereview.chromium.org/256923002/diff/1/chrome/browser/ui/views/tabs...
chrome/browser/ui/views/tabs/window_finder_win.cc:163: LocalProcessWindowFinder
finder(screen_loc_in_pixels, ignore);
Can we make LocalProcessWindowFinder and TopMostFinder take DIPs? If not, make
it clearer in descriptions that they take pixels, eg IsTopMostWindowAtPixel..

[ananta, 2014-04-28 18:13:07]

https://codereview.chromium.org/256923002/diff/1/chrome/browser/ui/views/tabs...
File chrome/browser/ui/views/tabs/window_finder_win.cc (right):

https://codereview.chromium.org/256923002/diff/1/chrome/browser/ui/views/tabs...
chrome/browser/ui/views/tabs/window_finder_win.cc:163: LocalProcessWindowFinder
finder(screen_loc_in_pixels, ignore);
On 2014/04/28 13:44:48, sky wrote:
> Can we make LocalProcessWindowFinder and TopMostFinder take DIPs? If not, make
> it clearer in descriptions that they take pixels, eg IsTopMostWindowAtPixel..

Done. Changed to continue passing in screen coordinates in DIPs. We convert to
pixels in the constructors of these classes.

[sky, 2014-04-28 20:26:25]

LGTM

[ananta, 2014-04-28 21:20:50]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2014-04-28 21:22:54]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ananta@chromium.org/256923002/20001

[commit-bot: I haz the power, 2014-04-28 22:06:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-28 22:06:02]

Try jobs failed on following builders:
  tryserver.chromium on chromium_presubmit

[ananta, 2014-04-28 23:06:22]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2014-04-28 23:07:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ananta@chromium.org/256923002/20001

[commit-bot: I haz the power, 2014-04-28 23:55:26]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-28 23:55:26]

Try jobs failed on following builders:
  tryserver.chromium on chromium_presubmit

[ananta, 2014-04-29 02:37:25]

Committed patchset #3 manually as r266744 (presubmit successful).