Use views::style for buttons, bootstrap ash_typography to do so.

chrome/browser/ui/views/harmony/harmony_typography_provider.cc

Index: chrome/browser/ui/views/harmony/harmony_typography_provider.cc
diff --git a/chrome/browser/ui/views/harmony/harmony_typography_provider.cc b/chrome/browser/ui/views/harmony/harmony_typography_provider.cc
index 21caf0cb832f7db4b16030d0338632a8d7852927..68eaa9836c66bb9155be2fffcaf41ef24e6c77fb 100644
--- a/chrome/browser/ui/views/harmony/harmony_typography_provider.cc
+++ b/chrome/browser/ui/views/harmony/harmony_typography_provider.cc
@@ -8,6 +8,10 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/platform_font.h"
 
+#if defined(USE_ASH)
+#include "ash/ash_typography.h"
+#endif
+
 const gfx::FontList& HarmonyTypographyProvider::GetFont(int text_context,
                                                         int text_style) const {
   // "Target" font size constants from the Harmony spec.
@@ -24,9 +28,14 @@ const gfx::FontList& HarmonyTypographyProvider::GetFont(int text_context,
 
   int size_delta = kDefaultSize - gfx::PlatformFont::kDefaultBaseFontSize;
   gfx::Font::Weight font_weight = gfx::Font::Weight::NORMAL;
+
+#if defined(USE_ASH)
+  ash::GetDefaultAshFont(text_context, text_style, &size_delta, &font_weight);
+#endif
+
   switch (text_context) {
-    case CONTEXT_HEADLINE:
-      size_delta = kHeadlineSize - gfx::PlatformFont::kDefaultBaseFontSize;
+    case views::style::CONTEXT_DIALOG_BUTTON:
+      font_weight = WeightNotLighterThanNormal(kButtonFontWeight);
       break;
     case views::style::CONTEXT_DIALOG_TITLE:
       size_delta = kTitleSize - gfx::PlatformFont::kDefaultBaseFontSize;
@@ -34,14 +43,15 @@ const gfx::FontList& HarmonyTypographyProvider::GetFont(int text_context,
     case CONTEXT_BODY_TEXT_LARGE:
       size_delta = kBodyTextLargeSize - gfx::PlatformFont::kDefaultBaseFontSize;
       break;
-    case views::style::CONTEXT_BUTTON:
-      font_weight = kButtonFontWeight;
+    case CONTEXT_HEADLINE:
+      size_delta = kHeadlineSize - gfx::PlatformFont::kDefaultBaseFontSize;
       break;
     default:
       break;
   }
 
   // Ignore |text_style| since it only affects color in the Harmony spec.
+
   return ui::ResourceBundle::GetSharedInstance().GetFontListWithDelta(
       size_delta, gfx::Font::NORMAL, font_weight);
 }
@@ -107,14 +117,14 @@ int HarmonyTypographyProvider::GetLineHeight(int text_context,
       kBodyTextSmallPlatformHeight + kBodyHeight;
 
   switch (text_context) {
-    case CONTEXT_HEADLINE:
-      return headline_height;
+    case views::style::CONTEXT_DIALOG_BUTTON:

[tapted, 2017/04/10 12:27:33]

There may still be a downside here to having LabelButton using CONTEXT_LABEL
rather than CONTEXT_DIALOG_BUTTON :/

GetLineHeight() can no longer distinguish LabelButton (and its subclasses) from
views::Label, and so it may provide a line spacing here that buttons never want.
E.g. this could change the minimum height a LabelButton can have, since its
label will now always want to have the harmony-specified leading/line-height.

[Peter Kasting, 2017/04/10 22:56:02]

Yeah, it seems desirable to return 0 here for LabelButton.

+      return kButtonAbsoluteHeight;
     case views::style::CONTEXT_DIALOG_TITLE:
       return title_height;
     case CONTEXT_BODY_TEXT_LARGE:
       return body_large_height;
-    case views::style::CONTEXT_BUTTON:
-      return kButtonAbsoluteHeight;
+    case CONTEXT_HEADLINE:
+      return headline_height;
     default:
       return default_height;
   }