Added the Material Design ink drop ripple effect to the navigation buttons in the browser toolbar.

chrome/browser/ui/views/toolbar/toolbar_button.cc

Index: chrome/browser/ui/views/toolbar/toolbar_button.cc
diff --git a/chrome/browser/ui/views/toolbar/toolbar_button.cc b/chrome/browser/ui/views/toolbar/toolbar_button.cc
index cf2e626384f1695631238f10ba4d0867ef99b4f4..42652f6e077353e6940827f58b40452f32603abc 100644
--- a/chrome/browser/ui/views/toolbar/toolbar_button.cc
+++ b/chrome/browser/ui/views/toolbar/toolbar_button.cc
@@ -18,6 +18,7 @@
 #include "ui/gfx/display.h"
 #include "ui/gfx/screen.h"
 #include "ui/strings/grit/ui_strings.h"
+#include "ui/views/animation/ink_drop_animation_controller.h"
 #include "ui/views/controls/button/label_button_border.h"
 #include "ui/views/controls/menu/menu_item_view.h"
 #include "ui/views/controls/menu/menu_model_adapter.h"
@@ -30,7 +31,16 @@ ToolbarButton::ToolbarButton(views::ButtonListener* listener,
       model_(model),
       menu_showing_(false),
       y_position_on_lbuttondown_(0),
+      ink_drop_animation_controller_(nullptr),

[Peter Kasting, 2015/07/17 18:01:58]

Omit this.

[bruthig, 2015/07/20 14:53:07]

Done.

       show_menu_factory_(this) {
+#if defined(OS_CHROMEOS)

[Peter Kasting, 2015/07/17 18:01:58]

Why is this OS_CHROMEOS?  Can't we do this for all platforms when mode ==
material?

[bruthig, 2015/07/20 14:53:07]

The designers want the ripple effect on Chrome OS only for the time being. 
There is concern that it will conflict with operating system touch feedback on
other OS's such as Windows 10.

+  if (ui::MaterialDesignController::IsModeMaterial()) {
+    ink_drop_animation_controller_.reset(
+        new views::InkDropAnimationController(this));
+    layer()->SetFillsBoundsOpaquely(false);

[Peter Kasting, 2015/07/17 18:01:58]

Why do we need this if it's unconditionally done on line 55?

[bruthig, 2015/07/20 14:53:07]

Line 55 is operating on image() whereas this is operating on layer().

I have moved them both here so as to save a layer when running in non-material
mode.

+  }
+#endif  // defined(OS_CHROMEOS)
+
   set_context_menu_controller(this);
 }
 
@@ -41,6 +51,8 @@ void ToolbarButton::Init() {
   SetFocusable(false);
   SetAccessibilityFocusable(true);
   image()->EnableCanvasFlippingForRTLUI(true);
+  image()->SetPaintToLayer(true);
+  image()->SetFillsBoundsOpaquely(false);
 }
 
 void ToolbarButton::ClearPendingMenu() {
@@ -148,6 +160,15 @@ ToolbarButton::CreateDefaultBorder() const {
   scoped_ptr<views::LabelButtonBorder> border =
       LabelButton::CreateDefaultBorder();
 
+  if (ui::MaterialDesignController::IsModeMaterial()) {

[Peter Kasting, 2015/07/17 18:01:58]

I suggest adding a comment on this block as to why we need to null the border
painters in material mode.

[bruthig, 2015/07/20 14:53:07]

Done.

+    border->SetPainter(true, Button::STATE_HOVERED, nullptr);
+    border->SetPainter(false, Button::STATE_HOVERED, nullptr);
+#if defined(OS_CHROMEOS)
+    border->SetPainter(true, Button::STATE_PRESSED, nullptr);
+    border->SetPainter(false, Button::STATE_PRESSED, nullptr);
+#endif  // defined(OS_CHROMEOS)
+  }
+
   ui::ThemeProvider* provider = GetThemeProvider();
   if (provider && provider->UsingSystemTheme()) {
     // Theme provided insets.