Fix window shadows.

content/browser/renderer_host/render_widget_host_view_mac.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.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #include <QuartzCore/QuartzCore.h>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
@@ skipping 937 matching lines @@
                                                    width,
                                                    height,
                                                    transport_dib);
 }
 
 void RenderWidgetHostViewMac::CompositorSwapBuffers(uint64 surface_handle,
                                                     int32 route_id,
                                                     int32 gpu_host_id) {
   pending_swap_buffers_acks_.push_back(std::make_pair(route_id, gpu_host_id));
   if (!compositing_iosurface_.get() && !is_hidden_) {
-    [cocoa_view_ addedGLContext];
     compositing_iosurface_.reset(CompositingIOSurfaceMac::Create());
   }
 
   if (compositing_iosurface_.get() && !is_hidden_) {
     last_frame_was_accelerated_ = true;
     compositing_iosurface_->SetIOSurface(surface_handle);
     [cocoa_view_ setNeedsDisplay:YES];
   } else {
     AckPendingCompositorSwapBuffers();
   }
@@ skipping 251 matching lines @@
   if (self) {
     editCommand_helper_.reset(new RenderWidgetHostViewMacEditCommandHelper);
     editCommand_helper_->AddEditingSelectorsToClass([self class]);
 
     renderWidgetHostView_.reset(r);
     canBeKeyView_ = YES;
     focusedPluginIdentifier_ = -1;
 
     // OpenGL support:
     handlingGlobalFrameDidChange_ = NO;
-    hasGLContext_ = NO;
     [[NSNotificationCenter defaultCenter]
          addObserver:self
             selector:@selector(globalFrameDidChange:)
                 name:NSViewGlobalFrameDidChangeNotification
               object:self];
   }
   return self;
 }
 
 - (void)dealloc {
@@ skipping 516 matching lines @@
     for (NSView* subview in [self subviews]) {
       if (![subview isKindOfClass:[RenderWidgetHostViewCocoa class]])
         continue;  // Skip plugin views.
 
       [static_cast<RenderWidgetHostViewCocoa*>(subview)
           renderWidgetHostViewMac]->KillSelf();
     }
   }
 }
 
-// OpenGL support
-- (void)addedGLContext {
-  hasGLContext_ = YES;
-  if (![self isHiddenOrHasHiddenAncestor]) {
-    // Intentionally leak underlaySurface count so that the window never changes
-    // back to opaque. This is to prevent black/transparent flashing that
-    // appears during tab switching otherwise.
-    // TODO(jbates) Remove the underlaySurfaceAdded feature completely from
-    // ChromeBrowserWindow when the subtle gray line corner bug is fixed. Then
-    // the window can be permanently set to non-opaque. crbug.com/56154
-    if ([[self window] respondsToSelector:@selector(underlaySurfaceAdded)])
-      [static_cast<id>([self window]) underlaySurfaceAdded];
-  }
-}
-
 - (void)viewWillMoveToWindow:(NSWindow*)newWindow {
-  if (![self isHiddenOrHasHiddenAncestor]) {
-    // Intentionally leak underlaySurface count (see comment in addedGLContext).
-    if (hasGLContext_ &&
-        [newWindow respondsToSelector:@selector(underlaySurfaceAdded)])
-      [static_cast<id>(newWindow) underlaySurfaceAdded];
-  }
-
   // We're messing with the window, so do this to ensure no flashes. This one
   // prevents a flash when the current tab is closed.
   [[self window] disableScreenUpdatesUntilFlush];
 }
 
-- (void) globalFrameDidChange:(NSNotification*)notification {
+- (void)globalFrameDidChange:(NSNotification*)notification {
   if (handlingGlobalFrameDidChange_)
     return;
 
   handlingGlobalFrameDidChange_ = YES;
   if (renderWidgetHostView_->compositing_iosurface_.get())
     renderWidgetHostView_->compositing_iosurface_->GlobalFrameDidChange();
   handlingGlobalFrameDidChange_ = NO;
 }
 
 - (void)setFrameSize:(NSSize)newSize {
@@ skipping 1072 matching lines @@
   if (!string) return NO;
 
   // If the user is currently using an IME, confirm the IME input,
   // and then insert the text from the service, the same as TextEdit and Safari.
   [self confirmComposition];
   [self insertText:string];
   return YES;
 }
 
 @end