Broke out layout metric information from ViewsDelegate to LayoutProvider

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

+// Copyright 2017 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/harmony/chrome_layout_provider.h"
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/ui/views/harmony/chrome_typography.h"
+#include "chrome/browser/ui/views/harmony/harmony_layout_provider.h"
+#include "ui/base/material_design/material_design_controller.h"
+#include "ui/views/layout/layout_constants.h"
+
+// static
+ChromeLayoutProvider* ChromeLayoutProvider::Get() {
+  return static_cast<ChromeLayoutProvider*>(views::LayoutProvider::Get());
+}
+
+// static
+std::unique_ptr<views::LayoutProvider>
+ChromeLayoutProvider::CreateLayoutProvider() {
+  return ui::MaterialDesignController::IsSecondaryUiMaterial()
+             ? base::MakeUnique<HarmonyLayoutProvider>()
+             : base::MakeUnique<ChromeLayoutProvider>();
+}
+
+int ChromeLayoutProvider::GetDistanceMetric(int metric) const {
+  switch (metric) {
+    case views::DISTANCE_BUTTON_HORIZONTAL_PADDING:
+    case views::DISTANCE_CLOSE_BUTTON_MARGIN:
+    case views::DISTANCE_DIALOG_BUTTON_MINIMUM_WIDTH:
+    case views::DISTANCE_RELATED_BUTTON_HORIZONTAL:
+    case views::DISTANCE_RELATED_CONTROL_HORIZONTAL:
+    case views::DISTANCE_RELATED_CONTROL_VERTICAL:

[Peter Kasting, 2017/04/12 21:37:43]

Nit: I think it would be less fragile, maintenance-wise, to remove the explicit
values here and instead have a default case that makes the call-to-base-class. 
Since the base class still NOTREACHED()s on unknown values, we don't lose any
runtime safety that way.

[kylix_rd, 2017/04/13 16:45:42]

Done.

+      return views::LayoutProvider::GetDistanceMetric(metric);
+
+    case DISTANCE_RELATED_CONTROL_HORIZONTAL_SMALL:
+      return views::kRelatedControlSmallHorizontalSpacing;
+    case DISTANCE_RELATED_CONTROL_VERTICAL_SMALL:
+      return views::kRelatedControlSmallVerticalSpacing;
+    case DISTANCE_DIALOG_BUTTON_MARGIN:
+      return views::kButtonHEdgeMarginNew;
+    case DISTANCE_DIALOG_BUTTON_TOP:
+      return 0;
+    case DISTANCE_BUTTON_MAX_LINKABLE_WIDTH:
+      return 0;
+    case DISTANCE_BUTTON_MINIMUM_WIDTH:
+      return views::kMinimumButtonWidth;
+    case DISTANCE_RELATED_LABEL_HORIZONTAL:
+      return views::kItemLabelSpacing;
+    case DISTANCE_SUBSECTION_HORIZONTAL_INDENT:
+      return views::kCheckboxIndent;
+    case DISTANCE_PANEL_CONTENT_MARGIN:
+      return views::kPanelHorizMargin;
+    case DISTANCE_UNRELATED_CONTROL_HORIZONTAL:
+      return views::kUnrelatedControlHorizontalSpacing;
+    case DISTANCE_UNRELATED_CONTROL_HORIZONTAL_LARGE:
+      return views::kUnrelatedControlLargeHorizontalSpacing;
+    case DISTANCE_UNRELATED_CONTROL_VERTICAL:
+      return views::kUnrelatedControlVerticalSpacing;
+    case DISTANCE_UNRELATED_CONTROL_VERTICAL_LARGE:
+      return views::kUnrelatedControlLargeVerticalSpacing;
+  }
+  NOTREACHED();
+  return 0;
+}
+
+const views::TypographyProvider& ChromeLayoutProvider::GetTypographyProvider()
+    const {
+  // This is not a data member because then HarmonyLayoutProvider would inherit
+  // it, even when it provides its own.
+  CR_DEFINE_STATIC_LOCAL(LegacyTypographyProvider, legacy_provider, ());
+  return legacy_provider;
+}
+
+views::GridLayout::Alignment
+ChromeLayoutProvider::GetControlLabelGridAlignment() const {
+  return views::GridLayout::TRAILING;
+}
+
+bool ChromeLayoutProvider::UseExtraDialogPadding() const {
+  return true;
+}
+
+bool ChromeLayoutProvider::ShouldShowWindowIcon() const {
+  return true;
+}
+
+bool ChromeLayoutProvider::IsHarmonyMode() const {
+  return false;
+}
+
+int ChromeLayoutProvider::GetDialogPreferredWidth(DialogWidth width) const {
+  return 0;
+}