Broke out layout metric information from ViewsDelegate to LayoutProvider

chrome/browser/ui/views/harmony/harmony_views_layout_delegate.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/harmony_views_layout_delegate.h"
+
+gfx::Insets HarmonyViewsLayoutDelegate::GetInsetsMetric(
+    ChromeInsetsMetric metric) const {
+  switch (metric) {
+    case ChromeInsetsMetric::DIALOG_BUTTON:
+    case ChromeInsetsMetric::PANEL_LAYOUT:
+    case ChromeInsetsMetric::BUBBLE_DIALOG:
+      return gfx::Insets(kHarmonyLayoutUnit);
+    case ChromeInsetsMetric::DIALOG_FRAME_VIEW: {
+      constexpr int top = kHarmonyLayoutUnit;
+      constexpr int side = kHarmonyLayoutUnit;
+      // Titles are inset at the top and sides, but not at the bottom.
+      return gfx::Insets(top, side, 0, side);
+    }
+    case ChromeInsetsMetric::VECTOR_IMAGE_BUTTON:
+      return gfx::Insets(kHarmonyLayoutUnit / 4);
+  }
+  NOTREACHED();
+  return gfx::Insets();
+}
+
+int HarmonyViewsLayoutDelegate::GetDistanceMetric(
+    ChromeDistanceMetric metric) const {
+  switch (metric) {
+    case ChromeDistanceMetric::CLOSE_BUTTON_MARGIN: {
+      constexpr int kVisibleMargin = kHarmonyLayoutUnit / 2;
+      // The visible margin is based on the unpadded size, so to get the actual
+      // margin we need to subtract out the padding.
+      return kVisibleMargin - kHarmonyLayoutUnit / 4;

[Peter Kasting, 2017/04/04 02:08:54]

Nit: Should probably refer to the VECTOR_IMAGE_BUTTON insets

I was kicking around whether having a few more distance metrics (some of the
ones that got removed) would let the base class define the insets in terms of
GetDistanceMetric() calls.  Then this class wouldn't need to override
GetInsetsMetric() at all because it would Just Do The Right Thing.  I'm not sure
whether this is worth it, but if we went this route, then the kHarmonyLayoutUnit
/ 4 bit would become a distance metric and you could refer to that here instead
of reading the route off the insets.

Incidentally, if these distance metrics were only to be used by the
implementation of GetInsetsMetric()/GetDistanceMetric(), and you used non-class
enums for the actual metrics, then you could easily define a set of "protected
identifiers" in the base class, and they'd be usable by subclasses but not
external callers.  (I'm sorry if I sound like a broken record on the enum issue,
it merely occurs to me that it would facilitate this.)

+    }
+    case ChromeDistanceMetric::RELATED_BUTTON_HORIZONTAL:

[Peter Kasting, 2017/04/04 02:08:54]

Nit: Might make sense to collapse together cases that return the same value. 
Not only is this shorter, once Harmony is the only style it will make it clearer
which metrics are just conceptual relics and should be merged into others.

[kylix_rd, 2017/04/04 20:28:23]

I thought doing about that. I was just concerned that some of these metrics are
still in a state of flux while the Harmony specs are mapped to real-world
metrics. Once they're nailed down, we can coalesce the like-valued items. Are
you confident that there will be no more changes?

[Peter Kasting, 2017/04/05 19:30:10]

Not 100% confident, but I think at most one or two values might change at this
point.  I'd go ahead and collapse them.

+      return kHarmonyLayoutUnit / 2;
+    case ChromeDistanceMetric::RELATED_CONTROL_HORIZONTAL:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::RELATED_CONTROL_HORIZONTAL_SMALL:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::RELATED_CONTROL_VERTICAL:
+      return kHarmonyLayoutUnit / 2;
+    case ChromeDistanceMetric::RELATED_CONTROL_VERTICAL_SMALL:
+      return kHarmonyLayoutUnit / 2;
+    case ChromeDistanceMetric::DIALOG_BUTTON_MARGIN:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::DIALOG_BUTTON_TOP:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::DIALOG_BUTTON_MINIMUM_WIDTH:
+    case ChromeDistanceMetric::BUTTON_MINIMUM_WIDTH:
+      // Minimum label size plus padding.
+      return 2 * kHarmonyLayoutUnit +
+             2 * GetDistanceMetric(
+                     ChromeDistanceMetric::BUTTON_HORIZONTAL_PADDING);
+    case ChromeDistanceMetric::BUTTON_HORIZONTAL_PADDING:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::BUTTON_MAX_LINKABLE_WIDTH:
+      return kHarmonyLayoutUnit * 8;
+    case ChromeDistanceMetric::RELATED_LABEL_HORIZONTAL:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::SUBSECTION_HORIZONTAL_INDENT:
+      return 0;
+    case ChromeDistanceMetric::PANEL_CONTENT_MARGIN:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::UNRELATED_CONTROL_HORIZONTAL:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::UNRELATED_CONTROL_HORIZONTAL_LARGE:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::UNRELATED_CONTROL_VERTICAL:
+      return kHarmonyLayoutUnit;
+    case ChromeDistanceMetric::UNRELATED_CONTROL_VERTICAL_LARGE:
+      return kHarmonyLayoutUnit;
+  }
+  NOTREACHED();
+  return 0;
+}
+views::GridLayout::Alignment
+HarmonyViewsLayoutDelegate::GetControlLabelGridAlignment() const {
+  return views::GridLayout::LEADING;
+}
+
+bool HarmonyViewsLayoutDelegate::UseExtraDialogPadding() const {
+  return false;
+}
+
+bool HarmonyViewsLayoutDelegate::ShouldShowWindowIcon() const {
+  return false;
+}
+
+bool HarmonyViewsLayoutDelegate::IsHarmonyMode() const {
+  return true;
+}
+
+int HarmonyViewsLayoutDelegate::GetDialogPreferredWidth(
+    DialogWidth width) const {
+  switch (width) {
+    case DialogWidth::SMALL:
+      return 320;
+    case DialogWidth::MEDIUM:
+      return 448;
+    case DialogWidth::LARGE:
+      return 512;
+  }
+  NOTREACHED();
+  return 0;
+}