[gtk] spoof proof infobars, take 2

This looks like a big review, but a lot of it is just shuffling code around:
- rip out dropshadow code
- move arrow state and drawing to a model class, to allow sharing between BrowserWindow and Infobar
- get rid of InfoBar's border_bin_ and slightly simplify baseclasses by no longer requiring them to call show() on the toplevel widget

Added stuff:
- transition between arrow colors (previous_color_ vs. target_color_ business)
- arrows protruding on neighboring infobars

BUG=48996
TEST=manual, with animations slowed down 100x

Review URL: http://codereview.chromium.org/3919004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@63956 0039d316-1c4b-4281-b951-d872f2087c98

25 files changed, 426 insertions, 317 deletions

diff --git a/chrome/browser/gtk/browser_window_gtk.cc b/chrome/browser/gtk/browser_window_gtk.cc
index 1dfc8f3..16c0f1a 100644
--- a/chrome/browser/gtk/browser_window_gtk.cc
+++ b/chrome/browser/gtk/browser_window_gtk.cc
@@ -81,8 +81,6 @@
 #include "chrome/common/native_web_keyboard_event.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/pref_names.h"
-#include "gfx/canvas_skia_paint.h"
-#include "gfx/color_utils.h"
 #include "gfx/gtk_util.h"
 #include "gfx/rect.h"
 #include "gfx/skia_utils_gtk.h"
@@ -90,7 +88,6 @@
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
-#include "third_party/skia/include/effects/SkGradientShader.h"
 
 namespace {
 
@@ -261,10 +258,6 @@ GdkCursorType GdkWindowEdgeToGdkCursorType(GdkWindowEdge edge) {
   return GDK_LAST_CURSOR;
 }
 
-GdkColor SkColorToGdkColor(const SkColor& color) {
-  return gfx::SkColorToGdkColor(color);
-}
-
 // A helper method for setting the GtkWindow size that should be used in place
 // of calling gtk_window_resize directly.  This is done to avoid a WM "feature"
 // where setting the window size to the monitor size causes the WM to set the
@@ -345,7 +338,7 @@ BrowserWindowGtk::BrowserWindowGtk(Browser* browser)
        maximize_after_show_(false),
        suppress_window_raise_(false),
        accel_group_(NULL),
-       infobar_animation_(this) {
+       infobar_arrow_model_(this) {
   // We register first so that other views like the toolbar can use the
   // is_active() function in their ActiveWindowChanged() handlers.
   ActiveWindowWatcherX::AddObserver(this);
@@ -389,8 +382,6 @@ BrowserWindowGtk::BrowserWindowGtk(Browser* browser)
   SetBackgroundColor();
   HideUnsupportedWindowFeatures();
 
-  infobar_animation_.SetTweenType(Tween::LINEAR);
-
   registrar_.Add(this, NotificationType::BOOKMARK_BAR_VISIBILITY_PREF_CHANGED,
                  NotificationService::AllSources());
 }
@@ -1680,7 +1671,7 @@ void BrowserWindowGtk::SetBackgroundColor() {
   SkColor frame_color = theme_provider->GetColor(frame_color_id);
 
   // Paint the frame color on the left, right and bottom.
-  GdkColor frame_color_gdk = SkColorToGdkColor(frame_color);
+  GdkColor frame_color_gdk = gfx::SkColorToGdkColor(frame_color);
   gtk_widget_modify_bg(GTK_WIDGET(window_), GTK_STATE_NORMAL,
                        &frame_color_gdk);
 
@@ -1692,7 +1683,8 @@ void BrowserWindowGtk::SetBackgroundColor() {
   // color, override the prelight also.
   color_utils::HSL hsl = { -1, 0.5, 0.65 };
   SkColor frame_prelight_color = color_utils::HSLShift(frame_color, hsl);
-  GdkColor frame_prelight_color_gdk = SkColorToGdkColor(frame_prelight_color);
+  GdkColor frame_prelight_color_gdk =
+      gfx::SkColorToGdkColor(frame_prelight_color);
   gtk_widget_modify_bg(contents_split_, GTK_STATE_PRELIGHT,
       &frame_prelight_color_gdk);
 
@@ -1798,179 +1790,74 @@ void BrowserWindowGtk::SaveWindowPosition() {
   window_preferences->SetInteger("work_area_bottom", work_area.bottom());
 }
 
-void BrowserWindowGtk::AnimationEnded(const Animation* animation) {
-  InvalidateInfoBarBits();
-}
-
-void BrowserWindowGtk::AnimationProgressed(const Animation* animation) {
-  InvalidateInfoBarBits();
-}
-
-void BrowserWindowGtk::AnimationCanceled(const Animation* animation) {
-  InvalidateInfoBarBits();
+void BrowserWindowGtk::SetInfoBarShowing(InfoBar* bar, bool animate) {
+  infobar_arrow_model_.ShowArrowFor(bar, animate);
 }
 
-void BrowserWindowGtk::SetInfoBarShowing(
-    const std::pair<SkColor, SkColor>* colors,
-    bool animate) {
-  if (colors) {
-    infobar_colors_ = *colors;
-
-    if (animate)
-      infobar_animation_.Show();
-    else
-      infobar_animation_.Reset(1.0);
-  } else {
-    if (animate)
-      infobar_animation_.Hide();
-    else
-      infobar_animation_.Reset();
-  }
-
+void BrowserWindowGtk::PaintStateChanged() {
   InvalidateInfoBarBits();
 }
 
-bool BrowserWindowGtk::ShouldDrawInfobarDropShadowOnRenderView() {
-  return infobar_animation_.GetCurrentValue() != 0.0 &&
-      !(bookmark_bar_.get() && bookmark_bar_is_floating_);
-}
-
 void BrowserWindowGtk::InvalidateInfoBarBits() {
   gtk_widget_queue_draw(toolbar_border_);
   gtk_widget_queue_draw(toolbar_->widget());
-  if (bookmark_bar_.get())
+  if (bookmark_bar_.get() && !bookmark_bar_is_floating_)
     gtk_widget_queue_draw(bookmark_bar_->widget());
+}
 
-  // Redraw the top bit of the render view area.
-  int width = contents_container_->widget()->allocation.width;
-  int height = gtk_util::kInfoBarDropShadowHeight;
-  gtk_widget_queue_draw_area(contents_container_->widget(),
-                             0, 0, width, height);
+int BrowserWindowGtk::GetXPositionOfLocationIcon(GtkWidget* relative_to) {
+  GtkWidget* location_icon = toolbar_->GetLocationBarView()->
+      location_icon_widget();
+  int x = 0;
+  gtk_widget_translate_coordinates(
+      location_icon, relative_to,
+      (location_icon->allocation.width + 1) / 2,
+      0, &x, NULL);
+
+  if (GTK_WIDGET_NO_WINDOW(relative_to))
+    x += relative_to->allocation.x;
+
+  return x;
 }
 
 gboolean BrowserWindowGtk::OnExposeDrawInfobarBits(GtkWidget* sender,
                                                    GdkEventExpose* expose) {
-  double alpha = infobar_animation_.GetCurrentValue();
-  if (alpha == 0.0)
+  if (!infobar_arrow_model_.NeedToDrawInfoBarArrow())
     return FALSE;
 
-  GtkWidget* location_icon = toolbar_->GetLocationBarView()->
-      location_icon_widget();
-  int x = 0;
-  int top_y = 0;
-  // The offset between the vertical center of the location icon and the top
-  // of the arrow.
-  const int kArrowVerticalOffset = 4;
-  gtk_widget_translate_coordinates(
-      location_icon, sender,
-      location_icon->allocation.width / 2,
-      location_icon->allocation.height / 2 + kArrowVerticalOffset,
-      &x, &top_y);
+  int x = GetXPositionOfLocationIcon(sender);
 
   gfx::Rect toolbar_border(toolbar_border_->allocation);
   int y = 0;
   gtk_widget_translate_coordinates(toolbar_border_, sender,
                                    0, toolbar_border.bottom(),
                                    NULL, &y);
-
-  int arrow_height = y - top_y;
-  // The width of half the arrow.
-  const int kArrowWidth = 15;
-
-  if (GTK_WIDGET_NO_WINDOW(sender)) {
-    x += sender->allocation.x;
+  if (GTK_WIDGET_NO_WINDOW(sender))
     y += sender->allocation.y;
-  }
-
-  SkPath path;
-  path.moveTo(SkPoint::Make(x - kArrowWidth, y));
-  path.lineTo(SkPoint::Make(x, y - arrow_height));
-  path.lineTo(SkPoint::Make(x + kArrowWidth, y));
-  path.close();
-
-  SkPaint paint;
-  paint.setStyle(SkPaint::kFill_Style);
-
-  SkPoint grad_points[2];
-  grad_points[0].set(SkIntToScalar(0), SkIntToScalar(y));
-  grad_points[1].set(SkIntToScalar(0),
-                     SkIntToScalar(y + InfoBar::kInfoBarHeight));
-
-  SkColor grad_colors[2];
-  grad_colors[0] = SkColorSetA(infobar_colors_.first, alpha * 0xff);
-  grad_colors[1] = SkColorSetA(infobar_colors_.second, alpha * 0xff);
-
-  SkShader* gradient_shader = SkGradientShader::CreateLinear(
-      grad_points, grad_colors, NULL, 2, SkShader::kMirror_TileMode);
-  paint.setShader(gradient_shader);
-  gradient_shader->unref();
-
-  gfx::CanvasSkiaPaint canvas(expose, false);
-  canvas.drawPath(path, paint);
-
-  paint.setShader(NULL);
-  paint.setStyle(SkPaint::kStroke_Style);
-  // Smooth out the shadow.
-  paint.setAntiAlias(true);
-
-  const int kMaxShading = 100;
-  const int kShadingPixels = 5;
-
-  // The goal of all this mathematical trickery is to create a shadow for the
-  // arrow that looks decent. We want a shadow of a set width, and the thickest
-  // direction of that shadow needs to be perpendicular to the sides of the
-  // arrow.
-  double scale_factor = sqrt(static_cast<double>(
-      (arrow_height * arrow_height + kArrowWidth * kArrowWidth))) /
-      kShadingPixels;
-  double x_scale = arrow_height / scale_factor / kShadingPixels;
-  double y_scale = kArrowWidth / scale_factor / kShadingPixels;
-  for (int i = 1; i <= kShadingPixels; ++i) {
-    double x_backoff = x_scale * i;
-    double y_backoff = y_scale * i;
-    SkPath shadow_path;
-    shadow_path.moveTo(0, y - i);
-    // The +1 below makes sure the shadow hugs the left side of the arrow.
-    shadow_path.rLineTo(x - kArrowWidth - x_backoff + 1, 0);
-    shadow_path.rMoveTo(0, i - y_backoff);
-    shadow_path.rLineTo(kArrowWidth, -arrow_height);
-    // The -1.5 below makes sure the shadow hugs the right side of the arrow.
-    shadow_path.rLineTo(2 * x_backoff - 1.5, 0);
-    shadow_path.rLineTo(kArrowWidth, arrow_height);
-    shadow_path.rMoveTo(0, y_backoff - i);
-    shadow_path.rLineTo(sender->allocation.width, 0);
-
-    int shading = (kShadingPixels - i + 1) * kMaxShading / kShadingPixels;
-    paint.setColor(SkColorSetARGB(alpha * shading, 0, 0, 0));
-    canvas.drawPath(shadow_path, paint);
-  }
 
+  Profile* profile = browser()->profile();
+  infobar_arrow_model_.Paint(
+      sender, expose, gfx::Point(x, y),
+      GtkThemeProvider::GetFrom(profile)->GetBorderColor());
   return FALSE;
 }
 
 gboolean BrowserWindowGtk::OnBookmarkBarExpose(GtkWidget* sender,
                                                GdkEventExpose* expose) {
-  if (infobar_animation_.GetCurrentValue() == 0.0)
+  if (!infobar_arrow_model_.NeedToDrawInfoBarArrow())
     return FALSE;
 
-  // This shares the same draw path as the other widgets when it's not floating.
-  if (!bookmark_bar_is_floating_)
-    return OnExposeDrawInfobarBits(sender, expose);
+  if (bookmark_bar_is_floating_)
+    return FALSE;
 
-  gfx::Point origin;
-  if (GTK_WIDGET_NO_WINDOW(sender))
-    origin = gfx::Point(sender->allocation.x, sender->allocation.y);
-  cairo_t* cr = gdk_cairo_create(GDK_DRAWABLE(expose->window));
-  gtk_util::DrawTopDropShadowForRenderView(cr, origin, gfx::Rect(expose->area));
-  cairo_destroy(cr);
-  return FALSE;
+  return OnExposeDrawInfobarBits(sender, expose);
 }
 
 void BrowserWindowGtk::OnBookmarkBarSizeAllocate(GtkWidget* sender,
                                                  GtkAllocation* allocation) {
   // The size of the bookmark bar affects how the infobar arrow is drawn on
   // the toolbar.
-  if (infobar_animation_.GetCurrentValue() != 0.0)
+  if (infobar_arrow_model_.NeedToDrawInfoBarArrow())
     gtk_widget_queue_draw(toolbar_->widget());
 }
 
diff --git a/chrome/browser/gtk/browser_window_gtk.h b/chrome/browser/gtk/browser_window_gtk.h
index ce6fd20..ce8e582 100644
--- a/chrome/browser/gtk/browser_window_gtk.h
+++ b/chrome/browser/gtk/browser_window_gtk.h
@@ -12,12 +12,12 @@
 
 #include "app/active_window_watcher_x.h"
 #include "app/gtk_signal.h"
-#include "app/slide_animation.h"
 #include "app/x11_util.h"
 #include "base/scoped_ptr.h"
 #include "base/timer.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_window.h"
+#include "chrome/browser/gtk/infobar_arrow_model.h"
 #include "chrome/browser/prefs/pref_member.h"
 #include "chrome/browser/tabs/tab_strip_model_observer.h"
 #include "chrome/common/notification_registrar.h"
@@ -45,7 +45,7 @@ class BrowserWindowGtk : public BrowserWindow,
                          public NotificationObserver,
                          public TabStripModelObserver,
                          public ActiveWindowWatcherX::Observer,
-                         public AnimationDelegate {
+                         public InfoBarArrowModel::Observer {
  public:
   explicit BrowserWindowGtk(Browser* browser);
   virtual ~BrowserWindowGtk();
@@ -145,10 +145,8 @@ class BrowserWindowGtk : public BrowserWindow,
   // Overridden from ActiveWindowWatcher::Observer.
   virtual void ActiveWindowChanged(GdkWindow* active_window);
 
-  // Overridden from AnimationDelegate.
-  virtual void AnimationEnded(const Animation* animation);
-  virtual void AnimationProgressed(const Animation* animation);
-  virtual void AnimationCanceled(const Animation* animation);
+  // Overridden from InfoBarArrowModel::Observer.
+  virtual void PaintStateChanged();
 
   // Accessor for the tab strip.
   TabStripGtk* tabstrip() const { return tabstrip_.get(); }
@@ -178,16 +176,9 @@ class BrowserWindowGtk : public BrowserWindow,
   // else for the custom frame.
   void ResetCustomFrameCursor();
 
-  // Toggles whether an infobar is showing. If |colors| is NULL, then no infobar
-  // is showing. When non-NULL, |colors| describes the gradient stop colors for
-  // the showing infobar.
-  // |animate| controls whether we animate to the new state set by |colors|.
-  void SetInfoBarShowing(const std::pair<SkColor, SkColor>* colors,
-                         bool animate);
-
-  // Called by the RenderViewHostDelegate::View (TabContentsViewGtk in our case)
-  // to decide whether to draw a drop shadow on the render view.
-  bool ShouldDrawInfobarDropShadowOnRenderView();
+  // Toggles whether an infobar is showing.
+  // |animate| controls whether we animate to the new state set by |bar|.
+  void SetInfoBarShowing(InfoBar* bar, bool animate);
 
   // Returns the BrowserWindowGtk registered with |window|.
   static BrowserWindowGtk* GetBrowserWindowForNativeWindow(
@@ -221,6 +212,10 @@ class BrowserWindowGtk : public BrowserWindow,
   // redraw when it should.
   void QueueToolbarRedraw();
 
+  // Get the position where the infobar arrow should be anchored in
+  // |relative_to| coordinates. This is the middle of the omnibox location icon.
+  int GetXPositionOfLocationIcon(GtkWidget* relative_to);
+
  protected:
   virtual void DestroyBrowser();
   // Top level window.
@@ -480,11 +475,9 @@ class BrowserWindowGtk : public BrowserWindow,
 
   scoped_ptr<FullscreenExitBubbleGtk> fullscreen_exit_bubble_;
 
-  // The top and bottom colors for the infobar gradient, if there is an
-  // infobar showing.
-  std::pair<SkColor, SkColor> infobar_colors_;
-
-  SlideAnimation infobar_animation_;
+  // The model that tracks the paint state of the arrow for the infobar
+  // directly below the toolbar.
+  InfoBarArrowModel infobar_arrow_model_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserWindowGtk);
 };
diff --git a/chrome/browser/gtk/extension_infobar_gtk.cc b/chrome/browser/gtk/extension_infobar_gtk.cc
index 7140afc..b7355b1 100644
--- a/chrome/browser/gtk/extension_infobar_gtk.cc
+++ b/chrome/browser/gtk/extension_infobar_gtk.cc
@@ -66,7 +66,6 @@ void ExtensionInfoBarGtk::BuildWidgets() {
 
   g_signal_connect(view_->native_view(), "size_allocate",
                    G_CALLBACK(&OnSizeAllocateThunk), this);
-  gtk_widget_show_all(border_bin_.get());
 }
 
 void ExtensionInfoBarGtk::OnSizeAllocate(GtkWidget* widget,
diff --git a/chrome/browser/gtk/gtk_util.cc b/chrome/browser/gtk/gtk_util.cc
index babed07..005c3b9 100644
--- a/chrome/browser/gtk/gtk_util.cc
+++ b/chrome/browser/gtk/gtk_util.cc
@@ -1136,25 +1136,4 @@ WebDragOperationsMask GdkDragActionToWebDragOp(GdkDragAction action) {
   return op;
 }
 
-void DrawTopDropShadowForRenderView(cairo_t* cr, const gfx::Point& origin,
-    const gfx::Rect& paint_rect) {
-  gfx::Rect shadow_rect(paint_rect.x(), origin.y(),
-                        paint_rect.width(), kInfoBarDropShadowHeight);
-
-  // Avoid this extra work if we can.
-  if (!shadow_rect.Intersects(paint_rect))
-    return;
-
-  cairo_pattern_t* shadow =
-      cairo_pattern_create_linear(0.0, shadow_rect.y(),
-                                  0.0, shadow_rect.bottom());
-  cairo_pattern_add_color_stop_rgba(shadow, 0, 0, 0, 0, 0.6);
-  cairo_pattern_add_color_stop_rgba(shadow, 1, 0, 0, 0, 0.1);
-  cairo_rectangle(cr, shadow_rect.x(), shadow_rect.y(),
-                  shadow_rect.width(), shadow_rect.height());
-  cairo_set_source(cr, shadow);
-  cairo_fill(cr);
-  cairo_pattern_destroy(shadow);
-}
-
 }  // namespace gtk_util
diff --git a/chrome/browser/gtk/gtk_util.h b/chrome/browser/gtk/gtk_util.h
index 466ba7e..0ecafee 100644
--- a/chrome/browser/gtk/gtk_util.h
+++ b/chrome/browser/gtk/gtk_util.h
@@ -57,9 +57,6 @@ const int kContentAreaSpacing = 18;
 // Horizontal Spacing between controls in a form.
 const int kFormControlSpacing = 10;
 
-// Height for the infobar drop shadow.
-const int kInfoBarDropShadowHeight = 6;
-
 // Create a table of labeled controls, using proper spacing and alignment.
 // Arguments should be pairs of const char*, GtkWidget*, concluding with a
 // NULL.  The first argument is a vector in which to place all labels
@@ -344,11 +341,6 @@ void InitLabelSizeRequestAndEllipsizeMode(GtkWidget* label);
 GdkDragAction WebDragOpToGdkDragAction(WebKit::WebDragOperationsMask op);
 WebKit::WebDragOperationsMask GdkDragActionToWebDragOp(GdkDragAction action);
 
-// Code to draw the drop shadow below an infobar (at the top of the render
-// view).
-void DrawTopDropShadowForRenderView(cairo_t* cr, const gfx::Point& origin,
-                                    const gfx::Rect& paint_rect);
-
 }  // namespace gtk_util
 
 #endif  // CHROME_BROWSER_GTK_GTK_UTIL_H_
diff --git a/chrome/browser/gtk/infobar_arrow_model.cc b/chrome/browser/gtk/infobar_arrow_model.cc
new file mode 100644
index 0000000..e66bb02
--- /dev/null
+++ b/chrome/browser/gtk/infobar_arrow_model.cc
@@ -0,0 +1,124 @@
+// Copyright (c) 2010 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/gtk/infobar_arrow_model.h"
+
+#include "chrome/browser/gtk/infobar_gtk.h"
+#include "gfx/canvas_skia_paint.h"
+#include "gfx/color_utils.h"
+#include "gfx/point.h"
+#include "gfx/skia_utils_gtk.h"
+#include "third_party/skia/include/effects/SkGradientShader.h"
+
+InfoBarArrowModel::InfoBarArrowModel(Observer* observer)
+    : observer_(observer),
+      animation_(this) {
+  animation_.SetTweenType(Tween::LINEAR);
+  animation_.Reset(1.0);
+  target_colors_.top = target_colors_.bottom = SkColorSetARGB(0, 0, 0, 0);
+  previous_colors_ = target_colors_;
+}
+
+InfoBarArrowModel::~InfoBarArrowModel() {
+}
+
+InfoBarArrowModel::InfoBarColors InfoBarArrowModel::CurrentInfoBarColors() {
+  double alpha = animation_.GetCurrentValue();
+  InfoBarColors colors = {
+      color_utils::AlphaBlend(target_colors_.top,
+                              previous_colors_.top,
+                              alpha * 0xff),
+      color_utils::AlphaBlend(target_colors_.bottom,
+                              previous_colors_.bottom,
+                              alpha * 0xff)};
+  return colors;
+}
+
+bool InfoBarArrowModel::NeedToDrawInfoBarArrow() {
+  return SkColorGetA(CurrentInfoBarColors().top) != 0;
+}
+
+void InfoBarArrowModel::ShowArrowFor(InfoBar* bar, bool animate) {
+  scoped_ptr<std::pair<SkColor, SkColor> > colors;
+
+  previous_colors_ = CurrentInfoBarColors();
+
+  if (bar) {
+    double r, g, b;
+    bar->GetTopColor(bar->delegate()->GetInfoBarType(), &r, &g, &b);
+    target_colors_.top = SkColorSetRGB(r * 0xff, g * 0xff, b * 0xff);
+    bar->GetBottomColor(bar->delegate()->GetInfoBarType(), &r, &g, &b);
+    target_colors_.bottom = SkColorSetRGB(r * 0xff, g * 0xff, b * 0xff);
+  } else {
+    target_colors_.bottom = target_colors_.top = SkColorSetARGB(0, 0, 0, 0);
+  }
+
+  if (animate) {
+    // Fade from the current color to the target color.
+    animation_.Reset();
+    animation_.Show();
+  } else {
+    // Skip straight to showing the target color.
+    animation_.Reset(1.0);
+  }
+
+  observer_->PaintStateChanged();
+}
+
+void InfoBarArrowModel::Paint(GtkWidget* widget,
+                              GdkEventExpose* expose,
+                              const gfx::Point& origin,
+                              const GdkColor& border_color) {
+  if (!NeedToDrawInfoBarArrow())
+    return;
+
+  // The size of the arrow (its height; also half its width).
+  const int kArrowSize = 10;
+
+  SkPath path;
+  path.moveTo(SkPoint::Make(origin.x() - kArrowSize, origin.y()));
+  path.rLineTo(kArrowSize, -kArrowSize);
+  path.rLineTo(kArrowSize, kArrowSize);
+  path.close();
+
+  SkPaint paint;
+  paint.setStrokeWidth(1);
+  paint.setStyle(SkPaint::kFill_Style);
+
+  SkPoint grad_points[2];
+  grad_points[0].set(SkIntToScalar(0), SkIntToScalar(origin.y()));
+  grad_points[1].set(SkIntToScalar(0),
+                     SkIntToScalar(origin.y() + InfoBar::kInfoBarHeight));
+
+  InfoBarColors colors = CurrentInfoBarColors();
+  SkColor grad_colors[2];
+  grad_colors[0] = colors.top;
+  grad_colors[1] = colors.bottom;
+
+  SkShader* gradient_shader = SkGradientShader::CreateLinear(
+      grad_points, grad_colors, NULL, 2, SkShader::kMirror_TileMode);
+  paint.setShader(gradient_shader);
+  gradient_shader->unref();
+
+  gfx::CanvasSkiaPaint canvas(expose, false);
+  canvas.drawPath(path, paint);
+
+  paint.setShader(NULL);
+  paint.setColor(SkColorSetA(gfx::GdkColorToSkColor(border_color),
+                             SkColorGetA(colors.top)));
+  paint.setStyle(SkPaint::kStroke_Style);
+  canvas.drawPath(path, paint);
+}
+
+void InfoBarArrowModel::AnimationEnded(const Animation* animation) {
+  observer_->PaintStateChanged();
+}
+
+void InfoBarArrowModel::AnimationProgressed(const Animation* animation) {
+  observer_->PaintStateChanged();
+}
+
+void InfoBarArrowModel::AnimationCanceled(const Animation* animation) {
+  observer_->PaintStateChanged();
+}
diff --git a/chrome/browser/gtk/infobar_arrow_model.h b/chrome/browser/gtk/infobar_arrow_model.h
new file mode 100644
index 0000000..369e586
--- /dev/null
+++ b/chrome/browser/gtk/infobar_arrow_model.h
@@ -0,0 +1,77 @@
+// Copyright (c) 2010 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.
+
+#ifndef CHROME_BROWSER_GTK_INFOBAR_ARROW_MODEL_H_
+#define CHROME_BROWSER_GTK_INFOBAR_ARROW_MODEL_H_
+
+#include <gtk/gtk.h>
+
+#include "app/slide_animation.h"
+#include "third_party/skia/include/core/SkPaint.h"
+
+namespace gfx {
+class Point;
+}
+
+class InfoBar;
+
+// A helper class that tracks the state of an infobar arrow and provides a
+// utility to draw it.
+class InfoBarArrowModel : public AnimationDelegate {
+ public:
+  class Observer {
+   public:
+    // The arrow has changed states; relevant widgets need to be repainted.
+    virtual void PaintStateChanged() = 0;
+  };
+
+  explicit InfoBarArrowModel(Observer* observer);
+  virtual ~InfoBarArrowModel();
+
+  // An infobar has been added or removed that will affect the state of this
+  // arrow.
+  void ShowArrowFor(InfoBar* bar, bool animate);
+
+  // Returns true if the arrow is showing at all.
+  bool NeedToDrawInfoBarArrow();
+
+  // Paints the arrow on |widget|, in response to |expose|, with the bottom
+  // center of the arrow at |origin|, drawing a border with |border_color|.
+  void Paint(GtkWidget* widget,
+             GdkEventExpose* expose,
+             const gfx::Point& origin,
+             const GdkColor& border_color);
+
+  // Overridden from AnimationDelegate.
+  virtual void AnimationEnded(const Animation* animation);
+  virtual void AnimationProgressed(const Animation* animation);
+  virtual void AnimationCanceled(const Animation* animation);
+
+ private:
+  // A pair of colors used to draw a gradient for an arrow.
+  struct InfoBarColors {
+    SkColor top;
+    SkColor bottom;
+  };
+
+  // Calculates the currently showing arrow color, which is a blend of the new
+  // arrow color and the old arrow color.
+  InfoBarColors CurrentInfoBarColors();
+
+  // The view that owns us.
+  Observer* observer_;
+
+  // An animation that tracks the progress of the transition from the last color
+  // to the new color.
+  SlideAnimation animation_;
+
+  // The color we are animating towards.
+  InfoBarColors target_colors_;
+  // The last color we showed (the one we are animating away from).
+  InfoBarColors previous_colors_;
+
+  DISALLOW_COPY_AND_ASSIGN(InfoBarArrowModel);
+};
+
+#endif  // CHROME_BROWSER_GTK_INFOBAR_ARROW_MODEL_H_
diff --git a/chrome/browser/gtk/infobar_container_gtk.cc b/chrome/browser/gtk/infobar_container_gtk.cc
index 01c6ccc..b53a995 100644
--- a/chrome/browser/gtk/infobar_container_gtk.cc
+++ b/chrome/browser/gtk/infobar_container_gtk.cc
@@ -143,6 +143,41 @@ void InfoBarContainerGtk::UpdateInfoBars() {
   }
 }
 
+void InfoBarContainerGtk::ShowArrowForDelegate(InfoBarDelegate* delegate,
+                                               bool animate) {
+  if (!CommandLine::ForCurrentProcess()->
+          HasSwitch(switches::kEnableSecureInfoBars)) {
+    return;
+  }
+
+  GList* children = gtk_container_get_children(GTK_CONTAINER(widget()));
+  if (!children)
+    return;
+
+  // Iterate through the infobars and find the last one that isn't closing.
+  InfoBar* last_bar = NULL;
+  InfoBar* this_bar = NULL;
+  for (GList* iter = children; iter != NULL; iter = iter->next) {
+    this_bar = reinterpret_cast<InfoBar*>(
+        g_object_get_data(G_OBJECT(iter->data), kInfoBar));
+
+    if (this_bar->delegate() == delegate)
+      break;
+
+    if (!this_bar->IsClosing())
+      last_bar = this_bar;
+
+    this_bar = NULL;
+  }
+
+  if (last_bar)
+    last_bar->ShowArrowFor(this_bar, animate);
+  else
+    UpdateToolbarInfoBarState(this_bar, animate);
+
+  g_list_free(children);
+}
+
 void InfoBarContainerGtk::AddInfoBar(InfoBarDelegate* delegate, bool animate) {
   InfoBar* infobar = delegate->CreateInfoBar();
   infobar->set_container(this);
@@ -155,8 +190,7 @@ void InfoBarContainerGtk::AddInfoBar(InfoBarDelegate* delegate, bool animate) {
   else
     infobar->Open();
 
-  if (tab_contents_->GetInfoBarDelegateAt(0) == delegate)
-    UpdateToolbarInfoBarState(infobar, animate);
+  ShowArrowForDelegate(delegate, animate);
 }
 
 void InfoBarContainerGtk::RemoveInfoBar(InfoBarDelegate* delegate,
@@ -169,21 +203,15 @@ void InfoBarContainerGtk::RemoveInfoBar(InfoBarDelegate* delegate,
                           delegate);
   }
 
-  if (tab_contents_->GetInfoBarDelegateAt(0) == delegate) {
-    InfoBar* bar = NULL;
-    // Get the next infobar, if it exists, so we can change the color of the
-    // arrow to it.
-    GList* children = gtk_container_get_children(GTK_CONTAINER(widget()));
-    if (children) {
-      if (children->next) {
-        bar = reinterpret_cast<InfoBar*>(
-            g_object_get_data(G_OBJECT(children->next->data), kInfoBar));
-      }
-      g_list_free(children);
+  InfoBarDelegate* next_delegate = NULL;
+  for (int i = 1; i < tab_contents_->infobar_delegate_count(); ++i) {
+    if (tab_contents_->GetInfoBarDelegateAt(i - 1) == delegate) {
+      next_delegate = tab_contents_->GetInfoBarDelegateAt(i);
+      break;
     }
-
-    UpdateToolbarInfoBarState(bar, animate);
   }
+
+  ShowArrowForDelegate(next_delegate, animate);
 }
 
 void InfoBarContainerGtk::UpdateToolbarInfoBarState(
@@ -193,21 +221,9 @@ void InfoBarContainerGtk::UpdateToolbarInfoBarState(
     return;
   }
 
-  scoped_ptr<std::pair<SkColor, SkColor> > colors;
-
-  if (infobar) {
-    double r, g, b;
-    infobar->GetTopColor(infobar->delegate()->GetInfoBarType(), &r, &g, &b);
-    SkColor top = SkColorSetRGB(r * 0xff, g * 0xff, b * 0xff);
-    infobar->GetBottomColor(infobar->delegate()->GetInfoBarType(), &r, &g, &b);
-    SkColor bottom = SkColorSetRGB(r * 0xff, g * 0xff, b * 0xff);
-
-    colors.reset(new std::pair<SkColor, SkColor>(top, bottom));
-  }
-
   GtkWindow* parent = platform_util::GetTopLevel(widget());
   BrowserWindowGtk* browser_window =
       BrowserWindowGtk::GetBrowserWindowForNativeWindow(parent);
   if (browser_window)
-    browser_window->SetInfoBarShowing(colors.get(), animate);
+    browser_window->SetInfoBarShowing(infobar, animate);
 }
diff --git a/chrome/browser/gtk/infobar_container_gtk.h b/chrome/browser/gtk/infobar_container_gtk.h
index cb81580..ba676a9 100644
--- a/chrome/browser/gtk/infobar_container_gtk.h
+++ b/chrome/browser/gtk/infobar_container_gtk.h
@@ -51,6 +51,10 @@ class InfoBarContainerGtk : public NotificationObserver {
   // this process.
   void UpdateInfoBars();
 
+  // Makes the calls to show an arrow for |delegate| (either on the browser
+  // toolbar or on the next infobar up).
+  void ShowArrowForDelegate(InfoBarDelegate* delegate, bool animate);
+
   // Adds an InfoBar for the specified delegate, in response to a notification
   // from the selected TabContents.
   void AddInfoBar(InfoBarDelegate* delegate, bool animate);
diff --git a/chrome/browser/gtk/infobar_gtk.cc b/chrome/browser/gtk/infobar_gtk.cc
index ce420ac..a512237 100644
--- a/chrome/browser/gtk/infobar_gtk.cc
+++ b/chrome/browser/gtk/infobar_gtk.cc
@@ -7,12 +7,14 @@
 #include <gtk/gtk.h>
 
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/gtk/browser_window_gtk.h"
 #include "chrome/browser/gtk/custom_button.h"
 #include "chrome/browser/gtk/gtk_chrome_link_button.h"
 #include "chrome/browser/gtk/gtk_chrome_shrinkable_hbox.h"
 #include "chrome/browser/gtk/gtk_theme_provider.h"
 #include "chrome/browser/gtk/gtk_util.h"
 #include "chrome/browser/gtk/infobar_container_gtk.h"
+#include "chrome/browser/platform_util.h"
 #include "chrome/common/notification_service.h"
 #include "gfx/gtk_util.h"
 
@@ -37,7 +39,8 @@ const int kRightPadding = 5;
 InfoBar::InfoBar(InfoBarDelegate* delegate)
     : container_(NULL),
       delegate_(delegate),
-      theme_provider_(NULL) {
+      theme_provider_(NULL),
+      arrow_model_(this) {
   // Create |hbox_| and pad the sides.
   hbox_ = gtk_hbox_new(FALSE, kElementPadding);
 
@@ -48,17 +51,13 @@ InfoBar::InfoBar(InfoBarDelegate* delegate)
   gtk_alignment_set_padding(GTK_ALIGNMENT(padding),
       0, 0, kLeftPadding, kRightPadding);
 
-  GtkWidget* bg_box = gtk_event_box_new();
-  gtk_widget_set_app_paintable(bg_box, TRUE);
-  g_signal_connect(bg_box, "expose-event",
+  bg_box_ = gtk_event_box_new();
+  gtk_widget_set_app_paintable(bg_box_, TRUE);
+  g_signal_connect(bg_box_, "expose-event",
                    G_CALLBACK(OnBackgroundExposeThunk), this);
   gtk_container_add(GTK_CONTAINER(padding), hbox_);
-  gtk_container_add(GTK_CONTAINER(bg_box), padding);
-  // The -1 on the kInfoBarHeight is to account for the border.
-  gtk_widget_set_size_request(bg_box, -1, kInfoBarHeight - 1);
-
-  border_bin_.Own(gtk_util::CreateGtkBorderBin(bg_box, NULL,
-                                               0, 1, 0, 0));
+  gtk_container_add(GTK_CONTAINER(bg_box_), padding);
+  gtk_widget_set_size_request(bg_box_, -1, kInfoBarHeight);
 
   // Add the icon on the left, if any.
   SkBitmap* icon = delegate->GetIcon();
@@ -69,13 +68,12 @@ InfoBar::InfoBar(InfoBarDelegate* delegate)
     gtk_box_pack_start(GTK_BOX(hbox_), image, FALSE, FALSE, 0);
   }
 
-  // TODO(erg): GTK theme the info bar.
   close_button_.reset(CustomDrawButton::CloseButton(NULL));
   gtk_util::CenterWidgetInHBox(hbox_, close_button_->widget(), true, 0);
   g_signal_connect(close_button_->widget(), "clicked",
                    G_CALLBACK(OnCloseButtonThunk), this);
 
-  slide_widget_.reset(new SlideAnimatorGtk(border_bin_.get(),
+  slide_widget_.reset(new SlideAnimatorGtk(bg_box_,
                                            SlideAnimatorGtk::DOWN,
                                            0, true, true, this));
   // We store a pointer back to |this| so we can refer to it from the infobar
@@ -84,7 +82,6 @@ InfoBar::InfoBar(InfoBarDelegate* delegate)
 }
 
 InfoBar::~InfoBar() {
-  border_bin_.Destroy();
 }
 
 GtkWidget* InfoBar::widget() {
@@ -93,14 +90,18 @@ GtkWidget* InfoBar::widget() {
 
 void InfoBar::AnimateOpen() {
   slide_widget_->Open();
-  if (border_bin_->window)
-    gdk_window_lower(border_bin_->window);
+
+  gtk_widget_show_all(bg_box_);
+  if (bg_box_->window)
+    gdk_window_lower(bg_box_->window);
 }
 
 void InfoBar::Open() {
   slide_widget_->OpenWithoutAnimation();
-  if (border_bin_->window)
-    gdk_window_lower(border_bin_->window);
+
+  gtk_widget_show_all(bg_box_);
+  if (bg_box_->window)
+    gdk_window_lower(bg_box_->window);
 }
 
 void InfoBar::AnimateClose() {
@@ -119,6 +120,18 @@ bool InfoBar::IsAnimating() {
   return slide_widget_->IsAnimating();
 }
 
+bool InfoBar::IsClosing() {
+  return slide_widget_->IsClosing();
+}
+
+void InfoBar::ShowArrowFor(InfoBar* other, bool animate) {
+  arrow_model_.ShowArrowFor(other, animate);
+}
+
+void InfoBar::PaintStateChanged() {
+  gtk_widget_queue_draw(widget());
+}
+
 void InfoBar::RemoveInfoBar() const {
   container_->RemoveDelegate(delegate_);
 }
@@ -253,8 +266,7 @@ void InfoBar::GetBottomColor(InfoBarDelegate::Type type,
 }
 
 void InfoBar::UpdateBorderColor() {
-  GdkColor border_color = theme_provider_->GetBorderColor();
-  gtk_widget_modify_bg(border_bin_.get(), GTK_STATE_NORMAL, &border_color);
+  gtk_widget_queue_draw(widget());
 }
 
 void InfoBar::OnCloseButton(GtkWidget* button) {
@@ -263,11 +275,11 @@ void InfoBar::OnCloseButton(GtkWidget* button) {
   RemoveInfoBar();
 }
 
-gboolean InfoBar::OnBackgroundExpose(GtkWidget* widget,
+gboolean InfoBar::OnBackgroundExpose(GtkWidget* sender,
                                      GdkEventExpose* event) {
-  const int height = widget->allocation.height;
+  const int height = sender->allocation.height;
 
-  cairo_t* cr = gdk_cairo_create(GDK_DRAWABLE(widget->window));
+  cairo_t* cr = gdk_cairo_create(GDK_DRAWABLE(sender->window));
   gdk_cairo_rectangle(cr, &event->area);
   cairo_clip(cr);
 
@@ -285,8 +297,30 @@ gboolean InfoBar::OnBackgroundExpose(GtkWidget* widget,
   cairo_paint(cr);
   cairo_pattern_destroy(pattern);
 
+  // Draw the bottom border.
+  GdkColor border_color = theme_provider_->GetBorderColor();
+  cairo_set_source_rgb(cr, border_color.red / 65535.0,
+                           border_color.green / 65535.0,
+                           border_color.blue / 65535.0);
+  cairo_set_line_width(cr, 1.0);
+  int y = sender->allocation.height;
+  cairo_move_to(cr, 0, y - 0.5);
+  cairo_rel_line_to(cr, sender->allocation.width, 0);
+  cairo_stroke(cr);
+
   cairo_destroy(cr);
 
+  if (!arrow_model_.NeedToDrawInfoBarArrow())
+    return FALSE;
+
+  GtkWindow* parent = platform_util::GetTopLevel(widget());
+  BrowserWindowGtk* browser_window =
+      BrowserWindowGtk::GetBrowserWindowForNativeWindow(parent);
+  int x = browser_window ?
+      browser_window->GetXPositionOfLocationIcon(sender) : 0;
+
+  arrow_model_.Paint(sender, event, gfx::Point(x, y), border_color);
+
   return FALSE;
 }
 
@@ -297,7 +331,6 @@ class AlertInfoBar : public InfoBar {
   explicit AlertInfoBar(AlertInfoBarDelegate* delegate)
       : InfoBar(delegate) {
     AddLabelAndLink(delegate->GetMessageText(), string16(), NULL);
-    gtk_widget_show_all(border_bin_.get());
   }
 };
 
@@ -312,7 +345,6 @@ class LinkInfoBar : public InfoBar {
     string16 link_text = delegate->GetLinkText();
     AddLabelWithInlineLink(display_text, link_text, link_offset,
                            G_CALLBACK(OnLinkClick));
-    gtk_widget_show_all(border_bin_.get());
   }
 
  private:
@@ -371,8 +403,6 @@ ConfirmInfoBar::ConfirmInfoBar(ConfirmInfoBarDelegate* delegate)
   // 13.4px == 10pt @ 96dpi
   gtk_util::ForceFontSizePixels(GTK_CHROME_LINK_BUTTON(link)->label, 13.4);
   gtk_util::CenterWidgetInHBox(hbox_, link, true, kEndOfLabelSpacing);
-
-  gtk_widget_show_all(border_bin_.get());
 }
 
 void ConfirmInfoBar::AddButton(ConfirmInfoBarDelegate::InfoBarButton type) {
diff --git a/chrome/browser/gtk/infobar_gtk.h b/chrome/browser/gtk/infobar_gtk.h
index 5589f9e..4293ea8 100644
--- a/chrome/browser/gtk/infobar_gtk.h
+++ b/chrome/browser/gtk/infobar_gtk.h
@@ -7,13 +7,16 @@
 #pragma once
 
 #include "app/gtk_signal.h"
+#include "app/slide_animation.h"
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
+#include "chrome/browser/gtk/infobar_arrow_model.h"
 #include "chrome/browser/gtk/owned_widget_gtk.h"
 #include "chrome/browser/gtk/slide_animator_gtk.h"
 #include "chrome/browser/tab_contents/infobar_delegate.h"
 #include "chrome/common/notification_observer.h"
 #include "chrome/common/notification_registrar.h"
+#include "third_party/skia/include/core/SkPaint.h"
 
 class CustomDrawButton;
 class GtkThemeProvider;
@@ -21,7 +24,8 @@ class InfoBarContainerGtk;
 class InfoBarDelegate;
 
 class InfoBar : public SlideAnimatorGtk::Delegate,
-                public NotificationObserver {
+                public NotificationObserver,
+                public InfoBarArrowModel::Observer {
  public:
   explicit InfoBar(InfoBarDelegate* delegate);
   virtual ~InfoBar();
@@ -53,12 +57,22 @@ class InfoBar : public SlideAnimatorGtk::Delegate,
   // Returns true if the infobar is showing the its open or close animation.
   bool IsAnimating();
 
+  // Returns true if the infobar is showing the close animation.
+  bool IsClosing();
+
   void SetThemeProvider(GtkThemeProvider* theme_provider);
 
+  // Show an arrow that originates from another infobar (i.e. a bar was added
+  // below this one). If |other| is NULL, stop showing the arrow.
+  void ShowArrowFor(InfoBar* other, bool animate);
+
+  // InfoBarArrowModel::Observer implementation.
+  virtual void PaintStateChanged();
+
   // SlideAnimatorGtk::Delegate implementation.
   virtual void Closed();
 
-  // NotificationOPbserver implementation.
+  // NotificationObserver implementation.
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
@@ -95,8 +109,8 @@ class InfoBar : public SlideAnimatorGtk::Delegate,
   // The top level widget of the infobar.
   scoped_ptr<SlideAnimatorGtk> slide_widget_;
 
-  // The second highest level widget of the infobar.
-  OwnedWidgetGtk border_bin_;
+  // The second highest widget in the hierarchy (after the slide widget).
+  GtkWidget* bg_box_;
 
   // The hbox that holds infobar elements (button, text, icon, etc.).
   GtkWidget* hbox_;
@@ -113,6 +127,10 @@ class InfoBar : public SlideAnimatorGtk::Delegate,
   // The theme provider, used for getting border colors.
   GtkThemeProvider* theme_provider_;
 
+  // The model that tracks the paint state of the arrow for the infobar
+  // below this one (if it exists).
+  InfoBarArrowModel arrow_model_;
+
   NotificationRegistrar registrar_;
 
  private:
diff --git a/chrome/browser/gtk/translate/after_translate_infobar_gtk.cc b/chrome/browser/gtk/translate/after_translate_infobar_gtk.cc
index 6fefadd..914f2ca 100644
--- a/chrome/browser/gtk/translate/after_translate_infobar_gtk.cc
+++ b/chrome/browser/gtk/translate/after_translate_infobar_gtk.cc
@@ -62,8 +62,6 @@ void AfterTranslateInfoBar::Init() {
       l10n_util::GetStringUTF8(IDS_TRANSLATE_INFOBAR_REVERT).c_str());
   g_signal_connect(button, "clicked",G_CALLBACK(&OnRevertPressedThunk), this);
   gtk_box_pack_start(GTK_BOX(hbox), button, FALSE, FALSE, 0);
-
-  gtk_widget_show_all(border_bin_.get());
 }
 
 void AfterTranslateInfoBar::OnOriginalLanguageModified(GtkWidget* sender) {
diff --git a/chrome/browser/gtk/translate/before_translate_infobar_gtk.cc b/chrome/browser/gtk/translate/before_translate_infobar_gtk.cc
index c3a9b8a..75c668e 100644
--- a/chrome/browser/gtk/translate/before_translate_infobar_gtk.cc
+++ b/chrome/browser/gtk/translate/before_translate_infobar_gtk.cc
@@ -73,8 +73,6 @@ void BeforeTranslateInfoBar::Init() {
                      G_CALLBACK(&OnAlwaysTranslatePressedThunk), this);
     gtk_box_pack_start(GTK_BOX(hbox), button, FALSE, FALSE, 0);
   }
-
-  gtk_widget_show_all(border_bin_.get());
 }
 
 void BeforeTranslateInfoBar::OnLanguageModified(GtkWidget* sender) {
diff --git a/chrome/browser/gtk/translate/translate_message_infobar_gtk.cc b/chrome/browser/gtk/translate/translate_message_infobar_gtk.cc
index 22e800d..0f61bca 100644
--- a/chrome/browser/gtk/translate/translate_message_infobar_gtk.cc
+++ b/chrome/browser/gtk/translate/translate_message_infobar_gtk.cc
@@ -31,8 +31,6 @@ void TranslateMessageInfoBar::Init() {
     g_signal_connect(button, "clicked",G_CALLBACK(&OnButtonPressedThunk), this);
     gtk_box_pack_start(GTK_BOX(hbox), button, FALSE, FALSE, 0);
   }
-
-  gtk_widget_show_all(border_bin_.get());
 }
 
 void TranslateMessageInfoBar::OnButtonPressed(GtkWidget* sender) {
diff --git a/chrome/browser/renderer_host/render_view_host_delegate.cc b/chrome/browser/renderer_host/render_view_host_delegate.cc
index 19722a1..523fd8f 100644
--- a/chrome/browser/renderer_host/render_view_host_delegate.cc
+++ b/chrome/browser/renderer_host/render_view_host_delegate.cc
@@ -112,7 +112,3 @@ gfx::Rect RenderViewHostDelegate::GetRootWindowResizerRect() const {
 bool RenderViewHostDelegate::IsExternalTabContainer() const {
   return false;
 }
-
-bool RenderViewHostDelegate::View::ShouldDrawDropShadow() {
-  return false;
-}
diff --git a/chrome/browser/renderer_host/render_view_host_delegate.h b/chrome/browser/renderer_host/render_view_host_delegate.h
index 5332a83..93aabb0 100644
--- a/chrome/browser/renderer_host/render_view_host_delegate.h
+++ b/chrome/browser/renderer_host/render_view_host_delegate.h
@@ -209,10 +209,6 @@ class RenderViewHostDelegate {
     // The contents' preferred size changed.
     virtual void UpdatePreferredSize(const gfx::Size& pref_size) = 0;
 
-    // Called to determine whether the render view needs to draw a drop shadow
-    // at the top (currently used for infobars).
-    virtual bool ShouldDrawDropShadow();
-
    protected:
     virtual ~View() {}
   };
diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
index 2f5a7e9..cc8ef50 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -876,14 +876,7 @@ void RenderWidgetHostViewGtk::Paint(const gfx::Rect& damage_rect) {
     // period where this object isn't attached to a window but hasn't been
     // Destroy()ed yet and it receives paint messages...
     if (window) {
-      gfx::Rect drop_shadow_area(0, 0, kMaxWindowWidth,
-                                 gtk_util::kInfoBarDropShadowHeight);
-      bool drop_shadow = host_->IsRenderView() &&
-          static_cast<RenderViewHost*>(host_)->delegate()->GetViewDelegate()->
-              ShouldDrawDropShadow() &&
-          drop_shadow_area.Intersects(paint_rect);
-
-      if (!visually_deemphasized_ && !drop_shadow) {
+      if (!visually_deemphasized_) {
         // In the common case, use XCopyArea. We don't draw more than once, so
         // we don't need to double buffer.
         backing_store->XShowRect(
@@ -915,15 +908,9 @@ void RenderWidgetHostViewGtk::Paint(const gfx::Rect& damage_rect) {
         backing_store->CairoShowRect(damage_rect, GDK_DRAWABLE(window));
 
         cairo_t* cr = gdk_cairo_create(window);
-        if (visually_deemphasized_) {
-          gdk_cairo_rectangle(cr, &rect);
-          cairo_set_source_rgba(cr, 0, 0, 0, 0.7);
-          cairo_fill(cr);
-        }
-        if (drop_shadow) {
-          gtk_util::DrawTopDropShadowForRenderView(
-              cr, gfx::Point(), damage_rect);
-        }
+        gdk_cairo_rectangle(cr, &rect);
+        cairo_set_source_rgba(cr, 0, 0, 0, 0.7);
+        cairo_fill(cr);
         cairo_destroy(cr);
 
         gdk_window_end_paint(window);
diff --git a/chrome/browser/tab_contents/tab_contents_view.cc b/chrome/browser/tab_contents/tab_contents_view.cc
index 83eb7a4..47e71f2 100644
--- a/chrome/browser/tab_contents/tab_contents_view.cc
+++ b/chrome/browser/tab_contents/tab_contents_view.cc
@@ -113,10 +113,6 @@ bool TabContentsView::IsEventTracking() const {
   return false;
 }
 
-bool TabContentsView::ShouldDrawDropShadow() {
-  return false;
-}
-
 TabContentsView::TabContentsView() : tab_contents_(NULL) {}
 
 void TabContentsView::HandleKeyboardEvent(const NativeWebKeyboardEvent& event) {
diff --git a/chrome/browser/tab_contents/tab_contents_view.h b/chrome/browser/tab_contents/tab_contents_view.h
index 4550781..c6b9a61 100644
--- a/chrome/browser/tab_contents/tab_contents_view.h
+++ b/chrome/browser/tab_contents/tab_contents_view.h
@@ -153,8 +153,6 @@ class TabContentsView : public RenderViewHostDelegate::View {
   virtual bool IsEventTracking() const;
   virtual void CloseTabAfterEventTracking() {}
 
-  virtual bool ShouldDrawDropShadow();
-
  protected:
   TabContentsView();  // Abstract interface.
 
diff --git a/chrome/browser/tab_contents/tab_contents_view_gtk.cc b/chrome/browser/tab_contents/tab_contents_view_gtk.cc
index 2c8a276..7ec34e4 100644
--- a/chrome/browser/tab_contents/tab_contents_view_gtk.cc
+++ b/chrome/browser/tab_contents/tab_contents_view_gtk.cc
@@ -247,19 +247,6 @@ void TabContentsViewGtk::RestoreFocus() {
     SetInitialFocus();
 }
 
-bool TabContentsViewGtk::ShouldDrawDropShadow() {
-  GtkWindow* window = GetTopLevelNativeWindow();
-  if (!window)
-    return false;
-
-  BrowserWindowGtk* browser_window =
-      BrowserWindowGtk::GetBrowserWindowForNativeWindow(window);
-  if (!browser_window)
-    return false;
-
-  return browser_window->ShouldDrawInfobarDropShadowOnRenderView();
-}
-
 void TabContentsViewGtk::SetFocusedWidget(GtkWidget* widget) {
   focus_store_.SetWidget(widget);
 }
diff --git a/chrome/browser/tab_contents/tab_contents_view_gtk.h b/chrome/browser/tab_contents/tab_contents_view_gtk.h
index 2ea02ca..9a016a1 100644
--- a/chrome/browser/tab_contents/tab_contents_view_gtk.h
+++ b/chrome/browser/tab_contents/tab_contents_view_gtk.h
@@ -59,7 +59,6 @@ class TabContentsViewGtk : public TabContentsView,
   virtual void SetInitialFocus();
   virtual void StoreFocus();
   virtual void RestoreFocus();
-  virtual bool ShouldDrawDropShadow();
 
   // Backend implementation of RenderViewHostDelegate::View.
   virtual void ShowContextMenu(const ContextMenuParams& params);
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 6c92179..aa3c47c 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1845,6 +1845,8 @@
         'browser/gtk/info_bubble_gtk.h',
         'browser/gtk/info_bubble_accelerators_gtk.cc',
         'browser/gtk/info_bubble_accelerators_gtk.h',
+        'browser/gtk/infobar_arrow_model.cc',
+        'browser/gtk/infobar_arrow_model.h',
         'browser/gtk/infobar_container_gtk.cc',
         'browser/gtk/infobar_container_gtk.h',
         'browser/gtk/infobar_gtk.cc',
diff --git a/gfx/color_utils.cc b/gfx/color_utils.cc
index 268f556..73c585b 100644
--- a/gfx/color_utils.cc
+++ b/gfx/color_utils.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -256,13 +256,28 @@ SkColor AlphaBlend(SkColor foreground, SkColor background, SkAlpha alpha) {
     return background;
   if (alpha == 255)
     return foreground;
-  return SkColorSetRGB(
-    ((SkColorGetR(foreground) * alpha) +
-     (SkColorGetR(background) * (255 - alpha))) / 255,
-    ((SkColorGetG(foreground) * alpha) +
-     (SkColorGetG(background) * (255 - alpha))) / 255,
-    ((SkColorGetB(foreground) * alpha) +
-     (SkColorGetB(background) * (255 - alpha))) / 255);
+
+  int f_alpha = SkColorGetA(foreground);
+  int b_alpha = SkColorGetA(background);
+
+  double normalizer = (f_alpha * alpha + b_alpha * (255 - alpha)) / 255.0;
+  if (normalizer == 0.0)
+    return SkColorSetARGB(0, 0, 0, 0);
+
+  double f_weight = f_alpha * alpha / normalizer;
+  double b_weight = b_alpha * (255 - alpha) / normalizer;
+
+  double r = (SkColorGetR(foreground) * f_weight +
+              SkColorGetR(background) * b_weight) / 255.0;
+  double g = (SkColorGetG(foreground) * f_weight +
+              SkColorGetG(background) * b_weight) / 255.0;
+  double b = (SkColorGetB(foreground) * f_weight +
+              SkColorGetB(background) * b_weight) / 255.0;
+
+  return SkColorSetARGB(static_cast<int>(normalizer),
+                        static_cast<int>(r),
+                        static_cast<int>(g),
+                        static_cast<int>(b));
 }
 
 SkColor GetReadableColor(SkColor foreground, SkColor background) {
diff --git a/gfx/color_utils.h b/gfx/color_utils.h
index f511168..b6eb2da 100644
--- a/gfx/color_utils.h
+++ b/gfx/color_utils.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -58,7 +58,9 @@ SkColor GetAverageColorOfFavicon(SkBitmap* bitmap, SkAlpha alpha);
 void BuildLumaHistogram(SkBitmap* bitmap, int histogram[256]);
 
 // Returns a blend of the supplied colors, ranging from |background| (for
-// |alpha| == 0) to |foreground| (for |alpha| == 255).
+// |alpha| == 0) to |foreground| (for |alpha| == 255). The alpha channels of
+// the supplied colors are also taken into account, so the returned color may
+// be partially transparent.
 SkColor AlphaBlend(SkColor foreground, SkColor background, SkAlpha alpha);
 
 // Given a foreground and background color, try to return a foreground color
diff --git a/gfx/color_utils_unittest.cc b/gfx/color_utils_unittest.cc
index 363d700..30cf514 100644
--- a/gfx/color_utils_unittest.cc
+++ b/gfx/color_utils_unittest.cc
@@ -47,3 +47,21 @@ TEST(ColorUtils, ColorToHSLRegisterSpill) {
   EXPECT_EQ(153U, SkColorGetG(result));
   EXPECT_EQ(88U, SkColorGetB(result));
 }
+
+TEST(ColorUtils, AlphaBlend) {
+  SkColor fore = SkColorSetARGB(255, 200, 200, 200);
+  SkColor back = SkColorSetARGB(255, 100, 100, 100);
+
+  EXPECT_TRUE(color_utils::AlphaBlend(fore, back, 255) ==
+              fore);
+  EXPECT_TRUE(color_utils::AlphaBlend(fore, back, 0) ==
+              back);
+
+  // One is fully transparent, result is partially transparent.
+  back = SkColorSetA(back, 0);
+  EXPECT_EQ(136U, SkColorGetA(color_utils::AlphaBlend(fore, back, 136)));
+
+  // Both are fully transparent, result is fully transparent.
+  fore = SkColorSetA(fore, 0);
+  EXPECT_EQ(0U, SkColorGetA(color_utils::AlphaBlend(fore, back, 255)));
+}