ash: Add accelerator for snapping windows left/right.

ash/accelerators/accelerator_controller.cc

Index: ash/accelerators/accelerator_controller.cc
diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index afaaf9a197b536751199db1db9304b925a0dcd73..e0f9b4ce9a052a67606498cdda413580043c01aa 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -21,8 +21,10 @@
 #include "ash/system/brightness/brightness_control_delegate.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/volume_control_delegate.h"
+#include "ash/wm/property_util.h"
 #include "ash/wm/window_cycle_controller.h"
 #include "ash/wm/window_util.h"
+#include "ash/wm/workspace/snap_sizer.h"
 #include "base/command_line.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
@@ -388,6 +390,19 @@ bool AcceleratorController::AcceleratorPressed(
       if (shell->tray())
         return shell->focus_cycler()->FocusWidget(shell->tray()->GetWidget());
       break;
+    case SNAP_WINDOW_LEFT:
+    case SNAP_WINDOW_RIGHT: {
+      aura::Window* window = wm::GetActiveWindow();
+      if (!window)
+        break;
+      internal::SnapSizer sizer(window,
+          gfx::Point(),
+          action == SNAP_WINDOW_LEFT ? internal::SnapSizer::LEFT_EDGE :
+                                       internal::SnapSizer::RIGHT_EDGE,
+          shell->GetGridSize());
+      window->SetBounds(sizer.target_bounds());
+      break;
+    }
     case SHOW_OAK:
       if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAshEnableOak))
         oak::ShowOakWindow();