Adjust bookmark folder menu window if its parent button is partly off-screen to the left.

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/strings/sys_string_conversions.h"
 #import "chrome/browser/bookmarks/bookmark_model_factory.h"
@@ skipping 508 matching lines @@
         [[parentButton_ window]
             convertBaseToScreen:[parentButton_
                                     convertPoint:NSZeroPoint toView:nil]];
     NSPoint bookmarkBarBottomLeftInScreen =
         [[parentButton_ window]
             convertBaseToScreen:[[parentButton_ superview]
                                     convertPoint:NSZeroPoint toView:nil]];
     newWindowTopLeft = NSMakePoint(
         buttonBottomLeftInScreen.x + bookmarks::kBookmarkBarButtonOffset,
         bookmarkBarBottomLeftInScreen.y + bookmarks::kBookmarkBarMenuOffset);
-    // Make sure the window is on-screen; if not, push left.  It is
-    // intentional that top level folders "push left" slightly
+    // Make sure the window is on-screen; if not, push left or right. It is
+    // intentional that top level folders "push left" or "push right" slightly
     // different than subfolders.
     NSRect screenFrame = [screen_ visibleFrame];
+    // Test if window goes off-screen on the right side.
     CGFloat spillOff = (newWindowTopLeft.x + windowWidth) - NSMaxX(screenFrame);
     if (spillOff > 0.0) {
       newWindowTopLeft.x = std::max(newWindowTopLeft.x - spillOff,
                                     NSMinX(screenFrame));
+    } else if (newWindowTopLeft.x < NSMinX(screenFrame)) {
+      // For left side.
+      newWindowTopLeft.x = NSMinX(screenFrame);
     }
     // The menu looks bad when it is squeezed up against the bottom of the
     // screen and ends up being only a few pixels tall. If it meets the
     // threshold for this case, instead show the menu above the button.
     CGFloat availableVerticalSpace = newWindowTopLeft.y -
         (NSMinY(screenFrame) + bookmarks::kScrollWindowVerticalMargin);
     if ((availableVerticalSpace < kMinSqueezedMenuHeight) &&
         (windowHeight > availableVerticalSpace)) {
       newWindowTopLeft.y = std::min(
           newWindowTopLeft.y + windowHeight + NSHeight([parentButton_ frame]),
@@ skipping 1456 matching lines @@
 
 - (void)setIgnoreAnimations:(BOOL)ignore {
   ignoreAnimations_ = ignore;
 }
 
 - (BookmarkButton*)buttonThatMouseIsIn {
   return buttonThatMouseIsIn_;
 }
 
 @end  // BookmarkBarFolderController