Add ctrl+drag feature for allowing resizing window with exact positioning.

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 45941616afd1253577e050065d17283014b3a43b..d44c0842c986dffbf958464b2308f1b8837a2002 100644
--- a/ash/wm/window_resizer.cc
+++ b/ash/wm/window_resizer.cc
@@ -186,7 +186,8 @@ int WindowResizer::AlignToGridRoundDown(int location, int grid_size) {
 // static
 gfx::Rect WindowResizer::CalculateBoundsForDrag(
     const Details& details,
-    const gfx::Point& location) {
+    const gfx::Point& location,
+    bool disable_snap_to_grid) {
   if (!details.is_resizable)
     return details.initial_bounds;
 
@@ -196,7 +197,8 @@ gfx::Rect WindowResizer::CalculateBoundsForDrag(
   // The minimize size constraint may limit how much we change the window
   // position.  For example, dragging the left edge to the right should stop
   // repositioning the window when the minimize size is reached.
-  gfx::Size size = GetSizeForDrag(details, &delta_x, &delta_y);
+  gfx::Size size = GetSizeForDrag(details, &delta_x, &delta_y,
+                                  disable_snap_to_grid);
   gfx::Point origin = GetOriginForDrag(details, delta_x, delta_y);
 
   gfx::Rect new_bounds(origin, size);
@@ -257,15 +259,21 @@ gfx::Point WindowResizer::GetOriginForDrag(const Details& details,
 // static
 gfx::Size WindowResizer::GetSizeForDrag(const Details& details,
                                         int* delta_x,
-                                        int* delta_y) {
+                                        int* delta_y,
+                                        bool disable_snap_to_grid) {
   gfx::Size size = details.initial_bounds.size();
   if (details.bounds_change & kBoundsChange_Resizes) {
     gfx::Size min_size = details.window->delegate()->GetMinimumSize();
-    min_size.set_width(AlignToGridRoundUp(min_size.width(), details.grid_size));
-    min_size.set_height(AlignToGridRoundUp(min_size.height(),
-                                           details.grid_size));
-    size.SetSize(GetWidthForDrag(details, min_size.width(), delta_x),
-                 GetHeightForDrag(details, min_size.height(), delta_y));
+    min_size.set_width(
+        AlignToGridRoundUp(min_size.width(),
+                           disable_snap_to_grid ? 0 : details.grid_size));
+    min_size.set_height(
+        AlignToGridRoundUp(min_size.height(),
+                           disable_snap_to_grid? 0 : details.grid_size));
+    size.SetSize(GetWidthForDrag(details, min_size.width(), delta_x,
+                                 disable_snap_to_grid),
+                 GetHeightForDrag(details, min_size.height(), delta_y,
+                                  disable_snap_to_grid));
   }
   return size;
 }
@@ -273,13 +281,15 @@ gfx::Size WindowResizer::GetSizeForDrag(const Details& details,
 // static
 int WindowResizer::GetWidthForDrag(const Details& details,
                                    int min_width,
-                                   int* delta_x) {
+                                   int* delta_x,
+                                   bool disable_snap_to_grid) {
   int width = details.initial_bounds.width();
   if (details.size_change_direction & kBoundsChangeDirection_Horizontal) {
     // Along the right edge, positive delta_x increases the window size.
     int x_multiplier = IsRightEdge(details.window_component) ? 1 : -1;
     width += x_multiplier * (*delta_x);
-    int adjusted_width = AlignToGrid(width, details.grid_size);
+    int adjusted_width =
+        AlignToGrid(width, disable_snap_to_grid ? 0 : details.grid_size);
     if (adjusted_width != width) {
       *delta_x += -x_multiplier * (width - adjusted_width);
       width = adjusted_width;
@@ -306,13 +316,15 @@ int WindowResizer::GetWidthForDrag(const Details& details,
 // static
 int WindowResizer::GetHeightForDrag(const Details& details,
                                     int min_height,
-                                    int* delta_y) {
+                                    int* delta_y,
+                                    bool disable_snap_to_grid) {
   int height = details.initial_bounds.height();
   if (details.size_change_direction & kBoundsChangeDirection_Vertical) {
     // Along the bottom edge, positive delta_y increases the window size.
     int y_multiplier = IsBottomEdge(details.window_component) ? 1 : -1;
     height += y_multiplier * (*delta_y);
-    int adjusted_height = AlignToGrid(height, details.grid_size);
+    int adjusted_height =
+        AlignToGrid(height, disable_snap_to_grid ? 0 : details.grid_size);
     if (height != adjusted_height) {
       *delta_y += -y_multiplier * (height - adjusted_height);
       height = adjusted_height;