Make some updates to BM bar for MD.

chrome/browser/ui/views/bookmarks/bookmark_bar_instructions_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/bookmarks/bookmark_bar_instructions_view.h"
 
 #include <algorithm>
 
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/ui/bookmarks/bookmark_bar_instructions_delegate.h"
 #include "chrome/grit/generated_resources.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/material_design/material_design_controller.h"
 #include "ui/base/theme_provider.h"
+#include "ui/native_theme/native_theme.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/link.h"
 
 namespace {
 
 // Horizontal padding, in pixels, between the link and label.
-const int kViewPadding = 6;
+const int GetViewPadding() {
+  if (ui::MaterialDesignController::IsModeMaterial())
+    return views::Label(base::ASCIIToUTF16(" ")).GetPreferredSize().width();

[sky, 2015/10/26 23:56:38]

Can we cache this? We don't really support changing the fonts on the fly.

[Evan Stade, 2015/10/27 17:05:42]

hmm, you're right. I thought we did support live font size changes but it
appears not. Done.

+
+  // Pre-MD is hard-coded to 6px.
+  return 6;
+}
 
 }  // namespace
 
 BookmarkBarInstructionsView::BookmarkBarInstructionsView(
     BookmarkBarInstructionsDelegate* delegate)
     : delegate_(delegate),
       instructions_(NULL),
       import_link_(NULL),
       baseline_(-1),
       updated_colors_(false) {
   instructions_ = new views::Label(
       l10n_util::GetStringUTF16(IDS_BOOKMARKS_NO_ITEMS));
   instructions_->SetAutoColorReadabilityEnabled(false);
+  instructions_->SetHorizontalAlignment(gfx::ALIGN_LEFT);

[Evan Stade, 2015/10/22 21:52:12]

the left align here and below fixes some jiggling that occurs when you resize
the browser window (the horizontal alignment of the text changes slightly as the
point of elision changes and the label is on the default center alignment).

   AddChildView(instructions_);
 
   if (browser_defaults::kShowImportOnBookmarkBar) {
     import_link_ = new views::Link(
         l10n_util::GetStringUTF16(IDS_BOOKMARK_BAR_IMPORT_LINK));
     // We don't want the link to alter tab navigation.
     import_link_->SetFocusable(false);
     import_link_->set_listener(this);
     import_link_->set_context_menu_controller(this);
     import_link_->SetAutoColorReadabilityEnabled(false);
+    import_link_->SetHorizontalAlignment(gfx::ALIGN_LEFT);
     AddChildView(import_link_);
   }
 }
 
 gfx::Size BookmarkBarInstructionsView::GetPreferredSize() const {
   int ascent = 0, descent = 0, height = 0, width = 0;
   for (int i = 0; i < child_count(); ++i) {
     const views::View* view = child_at(i);
     gfx::Size pref = view->GetPreferredSize();
     int baseline = view->GetBaseline();
     if (baseline != -1) {
       ascent = std::max(ascent, baseline);
       descent = std::max(descent, pref.height() - baseline);
     } else {
       height = std::max(pref.height(), height);
     }
     width += pref.width();
   }
-  width += (child_count() - 1) * kViewPadding;
+  width += (child_count() - 1) * GetViewPadding();
   if (ascent != 0)
     height = std::max(ascent + descent, height);
   return gfx::Size(width, height);
 }
 
 void BookmarkBarInstructionsView::Layout() {
   int remaining_width = width();
   int x = 0;
   for (int i = 0; i < child_count(); ++i) {
     views::View* view = child_at(i);
     gfx::Size pref = view->GetPreferredSize();
     int baseline = view->GetBaseline();
     int y;
     if (baseline != -1 && baseline_ != -1)
       y = baseline_ - baseline;
     else
       y = (height() - pref.height()) / 2;
     int view_width = std::min(remaining_width, pref.width());
     view->SetBounds(x, y, view_width, pref.height());
-    x += view_width + kViewPadding;
+    x += view_width + GetViewPadding();
     remaining_width = std::max(0, width() - x);
   }
 }
 
 const char* BookmarkBarInstructionsView::GetClassName() const {
   return "BookmarkBarInstructionsView";
 }
 
 void BookmarkBarInstructionsView::OnThemeChanged() {
   UpdateColors();
@@ skipping 25 matching lines @@
 
 void BookmarkBarInstructionsView::UpdateColors() {
   // We don't always have a theme provider (ui tests, for example).
   const ui::ThemeProvider* theme_provider = GetThemeProvider();
   if (!theme_provider)
     return;
   updated_colors_ = true;
   SkColor text_color =
       theme_provider->GetColor(ThemeProperties::COLOR_BOOKMARK_TEXT);
   instructions_->SetEnabledColor(text_color);
-  if (import_link_)
+  if (!import_link_)
+    return;
+
+  if (!ui::MaterialDesignController::IsModeMaterial()) {
     import_link_->SetEnabledColor(text_color);
+  } else {
+    // For MD, use the default link color if it provides enough contrast. If
+    // contrast is too low, fall back to the bookmark text color and use an
+    // underline to make it obvious it's a link. The default color readability
+    // code (which only adjusts luminance) doesn't work well in this case.
+    SkColor bg = theme_provider->GetColor(
+        ThemeProperties::ThemeProperties::COLOR_TOOLBAR);
+    SkColor link_color =
+        GetNativeTheme()->GetSystemColor(ui::NativeTheme::kColorId_LinkEnabled);
+    bool link_has_contrast = color_utils::GetContrastRatio(link_color, bg) >=
+                             color_utils::kMinimumReadableContrastRatio;
+    import_link_->SetUnderline(!link_has_contrast);
+    import_link_->SetEnabledColor(link_has_contrast ? link_color : text_color);
+  }
 }