Dragging panels near screen edge

chrome/browser/extensions/api/tabs/tabs_api.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/tabs/tabs_api.h"
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 734 matching lines @@
       break;
     default:
       break;
   }
 
   gfx::Rect bounds;
   if (controller->window()->IsMinimized())
     bounds = controller->window()->GetRestoredBounds();
   else
     bounds = controller->window()->GetBounds();
+  // TODO: Updating bounds during a drag can cause problems and a more general
+  // solution is needed. See http://crbug.com/251813 .
   bool set_bounds = false;
 
   // Any part of the bounds can optionally be set by the caller.
   int bounds_val;
   if (update_props->HasKey(keys::kLeftKey)) {
     EXTENSION_FUNCTION_VALIDATE(update_props->GetInteger(
         keys::kLeftKey,
         &bounds_val));
-    bounds.set_x(bounds_val);
-    set_bounds = true;
+    if (bounds.x() != bounds_val) {
+      bounds.set_x(bounds_val);
+      set_bounds = true;
+    }
   }
 
   if (update_props->HasKey(keys::kTopKey)) {
     EXTENSION_FUNCTION_VALIDATE(update_props->GetInteger(
         keys::kTopKey,
         &bounds_val));
-    bounds.set_y(bounds_val);
-    set_bounds = true;
+    if (bounds.y() != bounds_val) {
+      bounds.set_y(bounds_val);
+      set_bounds = true;
+    }
   }
 
   if (update_props->HasKey(keys::kWidthKey)) {
     EXTENSION_FUNCTION_VALIDATE(update_props->GetInteger(
         keys::kWidthKey,
         &bounds_val));
-    bounds.set_width(bounds_val);
-    set_bounds = true;
+    if (bounds.width() != bounds_val) {
+      bounds.set_width(bounds_val);
+      set_bounds = true;
+    }
   }
 
   if (update_props->HasKey(keys::kHeightKey)) {
     EXTENSION_FUNCTION_VALIDATE(update_props->GetInteger(
         keys::kHeightKey,
         &bounds_val));
-    bounds.set_height(bounds_val);
-    set_bounds = true;
+    if (bounds.height() != bounds_val) {
+      bounds.set_height(bounds_val);
+      set_bounds = true;
+    }
   }
 
   if (set_bounds) {

[flackr, 2013/06/20 19:47:46]

FYI, this comment may be relevant as well:
https://code.google.com/p/chromium/codesearch#chromium/src/ui/aura/window.cc&...
There may be important side effects that setting the bounds again will cause.

     if (show_state == ui::SHOW_STATE_MINIMIZED ||
         show_state == ui::SHOW_STATE_MAXIMIZED ||
         show_state == ui::SHOW_STATE_FULLSCREEN) {
       error_ = keys::kInvalidWindowStateError;
       return false;
     }
     controller->window()->SetBounds(bounds);
   }
 
   bool active_val = false;
@@ skipping 1265 matching lines @@
   execute_tab_id_ = tab_id;
   details_ = details.Pass();
   return true;
 }
 
 bool TabsInsertCSSFunction::ShouldInsertCSS() const {
   return true;
 }
 
 }  // namespace extensions