First stab at touch optimized omnibox auto-complete per sgabriel's mocks.

chrome/browser/ui/views/autocomplete/touch_autocomplete_popup_contents_view.cc

Index: chrome/browser/ui/views/autocomplete/touch_autocomplete_popup_contents_view.cc
diff --git a/chrome/browser/ui/views/autocomplete/touch_autocomplete_popup_contents_view.cc b/chrome/browser/ui/views/autocomplete/touch_autocomplete_popup_contents_view.cc
index f5f3865147b5e22e077a862de3482697183325f8..f81ab859cf3c6dc5609397262c3f6e7d06479f29 100644
--- a/chrome/browser/ui/views/autocomplete/touch_autocomplete_popup_contents_view.cc
+++ b/chrome/browser/ui/views/autocomplete/touch_autocomplete_popup_contents_view.cc
@@ -13,7 +13,6 @@
 #include "ui/gfx/size.h"
 #include "ui/views/view.h"
 
-
 // TouchAutocompleteResultView ------------------------------------------------
 
 TouchAutocompleteResultView::TouchAutocompleteResultView(
@@ -22,6 +21,9 @@ TouchAutocompleteResultView::TouchAutocompleteResultView(
     const gfx::Font& font,
     const gfx::Font& bold_font)
     : AutocompleteResultView(model, model_index, font, bold_font) {
+  set_edge_item_padding(8);
+  set_item_padding(8);
+  set_minimum_text_vertical_padding(10);
 }
 
 TouchAutocompleteResultView::~TouchAutocompleteResultView() {
@@ -30,25 +32,26 @@ TouchAutocompleteResultView::~TouchAutocompleteResultView() {
 void TouchAutocompleteResultView::PaintMatch(gfx::Canvas* canvas,
                                              const AutocompleteMatch& match,
                                              int x) {
-  DrawString(canvas, match.contents, match.contents_class, false, x,
-             text_bounds().y());
+  int y = text_bounds().y();
 
   if (!match.description.empty()) {
     // We use our base class's GetTextHeight below because we need the height
     // of a single line of text.
-    DrawString(canvas, match.description, match.description_class, true, x,
-        text_bounds().y() + AutocompleteResultView::GetTextHeight());
+    DrawString(canvas, match.description, match.description_class, true, x, y);
+    y += AutocompleteResultView::GetTextHeight();
+  } else {
+    // When we have only one line of content (no description), we center the
+    // single line vertically on our two-lines-tall results box.
+    y += AutocompleteResultView::GetTextHeight() / 2;
   }
+
+  DrawString(canvas, match.contents, match.contents_class, false, x, y);
 }
 
 int TouchAutocompleteResultView::GetTextHeight() const {
-  // In the touch version of the autocomplete popup, the text is displayed in
-  // two lines: First line is the title of the suggestion and second is the
-  // description. Hence, the total text height is twice the height of one line.
   return AutocompleteResultView::GetTextHeight() * 2;
 }
 
-
 // TouchAutocompletePopupContentsView -----------------------------------------
 
 TouchAutocompletePopupContentsView::TouchAutocompletePopupContentsView(
@@ -68,19 +71,6 @@ void TouchAutocompletePopupContentsView::UpdatePopupAppearance() {
   Layout();
 }
 
-void TouchAutocompletePopupContentsView::LayoutChildren() {
-  std::vector<View*> visible_children(GetVisibleChildren());
-  gfx::Rect bounds(GetContentsBounds());
-  double child_width =
-      static_cast<double>(bounds.width()) / visible_children.size();
-  int x = bounds.x();
-  for (size_t i = 0; i < visible_children.size(); ++i) {
-    int next_x = bounds.x() + static_cast<int>(((i + 1) * child_width) + 0.5);
-    visible_children[i]->SetBounds(x, bounds.y(), next_x - x, bounds.height());
-    x = next_x;
-  }
-}
-
 void TouchAutocompletePopupContentsView::PaintResultViews(gfx::Canvas* canvas) {
   AutocompletePopupContentsView::PaintResultViews(canvas);
 
@@ -88,24 +78,45 @@ void TouchAutocompletePopupContentsView::PaintResultViews(gfx::Canvas* canvas) {
   std::vector<View*> visible_children(GetVisibleChildren());
   if (visible_children.size() < 2)
     return;
-  SkColor color = AutocompleteResultView::GetColor(
-      AutocompleteResultView::NORMAL, AutocompleteResultView::DIMMED_TEXT);
   gfx::Rect bounds(GetContentsBounds());
-  for (std::vector<View*>::const_iterator i(visible_children.begin() + 1);
-       i != visible_children.end(); ++i) {
-    canvas->DrawLine(gfx::Point((*i)->x(), bounds.y()),
-                     gfx::Point((*i)->x(), bounds.bottom()), color);
-  }
-}
 
-int TouchAutocompletePopupContentsView::CalculatePopupHeight() {
-  DCHECK_GE(static_cast<size_t>(child_count()), model_->result().size());
-  int popup_height = 0;
-  for (size_t i = 0; i < model_->result().size(); ++i) {
-    popup_height = std::max(popup_height,
-                            child_at(i)->GetPreferredSize().height());
+  // Normally, we draw dividers at the top of each child.  However, if
+  // the current item is selected or hovered, the divider color needs
+  // to blend with the background color of the current child, so we
+  // draw at the top and bottom of the current child and skip the line
+  // at the top of the next child.

[Peter Kasting, 2012/05/11 23:01:41]

Uff da.

Can we just do normal-colored dividers between each row regardless of selection
state?  This would make this code simpler, allow us to avoid making GetState()
non-private, let us calculate the color here instead of adding a DIVIDER enum
value, and probably still look fine (in fact, maybe better, as the current
system looks a bit weird).

Even if you really really like this color scheme, can we just loop over children
(0, n-1) drawing a line at the bottom of each one based on the state of both
children?  Note that this will also address a "bug" in the current code (IMO)
where the border between a selected and a hovered cell matches whichever is on
the bottom, where I think there should be a SELECTED > HOVERED > NORMAL
precedence order.

[Jói, 2012/05/11 23:09:24]

I tried with normal-colored dividers regardless of selection state, and it
doesn't look as good.

The current code has the precedence order you are suggesting.  The reason I
sometimes need to draw both top and bottom of the current child (and skip the
top of the following child) is to get that precedence order, and to draw the
divider on top of the right background color to blend with (if I draw it on the
next child it will be blended with that child's background color, which won't
look right).

[Jói, 2012/05/14 18:29:45]

I've changed this code as per your suggestion, it's a lot simpler now but the
visual end result is the same.

+  //
+  // We also skip the top line of the first child since there is
+  // already the dropdown border, and likewise we never draw a line at
+  // the bottom of the last child.
+  bool skip_next = true;
+  for (std::vector<View*>::const_iterator i(visible_children.begin());
+       i != visible_children.end(); ++i) {
+    TouchAutocompleteResultView* child =
+        static_cast<TouchAutocompleteResultView*>(*i);
+    SkColor divider_color = AutocompleteResultView::GetColor(
+        child->GetState(), AutocompleteResultView::DIVIDER);
+
+    if (!skip_next) {
+      canvas->DrawLine(
+          gfx::Point(bounds.x(), child->y()),
+          gfx::Point(bounds.right(), child->y()),
+          divider_color);
+    }
+
+    skip_next = false;
+
+    if ((child->GetState() == AutocompleteResultView::SELECTED ||
+        child->GetState() == AutocompleteResultView::HOVERED) &&
+        i + 1 != visible_children.end()) {
+      skip_next = true;
+
+      canvas->DrawLine(
+          gfx::Point(bounds.x(), child->y() + child->height() - 1),
+          gfx::Point(bounds.right(), child->y() + child->height() - 1),
+          divider_color);
+    }
   }
-  return popup_height;
 }
 
 AutocompleteResultView* TouchAutocompletePopupContentsView::CreateResultView(