[MD] Don't allow overflowing location icons to appear on top of toolbar

chrome/browser/ui/views/location_bar/location_bar_view.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/ui/views/location_bar/location_bar_view.h"
 
 #include <algorithm>
 #include <map>
 
 #include "base/i18n/rtl.h"
@@ skipping 161 matching lines @@
       ThemeProperties::GetDefaultColor(ThemeProperties::COLOR_TOOLBAR,
                                        incognito),
       SkColorGetA(kBorderColor));
 }
 
 void LocationBarView::Init() {
   // We need to be in a Widget, otherwise GetNativeTheme() may change and we're
   // not prepared for that.
   DCHECK(GetWidget());
 
-  if (!ui::MaterialDesignController::IsModeMaterial()) {
+  if (ui::MaterialDesignController::IsModeMaterial()) {
+    // Make sure children with layers are clipped.
+    SetPaintToLayer(true);

[bruthig, 2016/02/24 17:02:58]

Calling SetPaintToLayer(true) causes the View to create a
LayerType::LAYER_TEXTURED Layer which does have some associated costs, however,
I don't think View will currently work with a LAYER_NOT_DRAWN type Layer.  I
have filed http://crbug.com/589497 to address this issue on a more general
basis.  I suspect that it will require at least a moderate amount of effort to
solve this in the general case.
Can you add a TODO here (and maybe in the two other spots that use this
technique) that references that bug?

[Evan Stade, 2016/02/24 23:14:17]

done. (Only two spots use this technique AFAIK --- the infobar is a special case
as even without layers we had to do a special dance for clipping. This is a
result of the funky shape necessary to draw the arrow.)

+    SetFillsBoundsOpaquely(false);
+    layer()->SetMasksToBounds(true);
+  } else {

[Peter Kasting, 2016/02/24 01:46:08]

Nit: Can combine this else with subsequent if and flatten to one three-arm
conditional

[Evan Stade, 2016/02/24 23:14:18]

Done.

     if (is_popup_mode_) {
       const int kOmniboxPopupBorderImages[] =
           IMAGE_GRID(IDR_OMNIBOX_POPUP_BORDER_AND_SHADOW);
       border_painter_.reset(
           views::Painter::CreateImageGridPainter(kOmniboxPopupBorderImages));
     } else {
       ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
       const gfx::Insets omnibox_border_insets(14, 9, 14, 9);
       border_painter_.reset(views::Painter::CreateImagePainter(
           *rb.GetImageSkiaNamed(IDR_OMNIBOX_BORDER), omnibox_border_insets));
@@ skipping 1201 matching lines @@
 // LocationBarView, private TemplateURLServiceObserver implementation:
 
 void LocationBarView::OnTemplateURLServiceChanged() {
   template_url_service_->RemoveObserver(this);
   template_url_service_ = nullptr;
   // If the browser is no longer active, let's not show the info bubble, as this
   // would make the browser the active window again.
   if (omnibox_view_ && omnibox_view_->GetWidget()->IsActive())
     ShowFirstRunBubble();
 }