Adding proper dragging behavior for L/R maximized windows.

ash/wm/window_resizer.cc

Index: ash/wm/window_resizer.cc
diff --git a/ash/wm/window_resizer.cc b/ash/wm/window_resizer.cc
index 623be33368d37c62f586e765b8446787987e5609..0ecadc475ecf1182bf83d473027bd8962b6798a3 100644
--- a/ash/wm/window_resizer.cc
+++ b/ash/wm/window_resizer.cc
@@ -6,6 +6,8 @@
 
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
+#include "ash/wm/property_util.h"
+#include "ash/wm/window_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
@@ -100,6 +102,7 @@ const int WindowResizer::kBoundsChangeDirection_Vertical = 2;
 
 WindowResizer::Details::Details()
     : window(NULL),
+      restore_bounds(gfx::Rect()),
       window_component(HTNOWHERE),
       bounds_change(0),
       position_change_direction(0),
@@ -112,6 +115,7 @@ WindowResizer::Details::Details(aura::Window* window,
                                 int window_component)
   : window(window),
     initial_bounds(window->bounds()),
+    restore_bounds(gfx::Rect()),
     initial_location_in_parent(location),
     initial_opacity(window->layer()->opacity()),
     window_component(window_component),
@@ -121,6 +125,10 @@ WindowResizer::Details::Details(aura::Window* window,
     size_change_direction(
         GetSizeChangeDirectionForWindowComponent(window_component)),
     is_resizable(bounds_change != kBoundsChangeDirection_None) {
+  if (wm::IsWindowNormal(window) &&
+      GetRestoreBoundsInScreen(window) &&
+      window_component == HTCAPTION)
+    restore_bounds = *GetRestoreBoundsInScreen(window);
 }
 
 WindowResizer::Details::~Details() {
@@ -267,6 +275,9 @@ gfx::Size WindowResizer::GetSizeForDrag(const Details& details,
                                  grid_size),
                  GetHeightForDrag(details, min_size.height(), delta_y,
                                   grid_size));
+  } else {
+    if (!details.restore_bounds.IsEmpty())
+      size = details.restore_bounds.size();

[sky, 2012/09/06 19:45:11]

You may need to adjust the origin too. Consider the following: create a smallish
window, say 100x100, snap it to the left. Say it ends up with a width of 1024.
If you start dragging close the right, say 1000, the dragged window is going to
snap back to 100x100 and the window is no longer going to be under the mouse.

[Mr4D (OOO till 08-26), 2012/09/06 23:16:13]

I was first tempted to say that this was taken care off, but then realized that
you are right... Addressed.

   }
   return size;
 }