Change ChromeOS restored frame top to 8 DIP.

Change it to 8 from 7. Do this programmatically rather than with
hard-coded constants.

BUG=851101

Change-Id: I638dfcfc641c92af860f4b0d4e630914bc6426f9
Reviewed-on: https://chromium-review.googlesource.com/1137236Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575457}

ash/public/cpp/ash_layout_constants.cc

@@ -11,28 +11,19 @@ namespace ash {
 
 gfx::Size GetAshLayoutSize(AshLayoutSize size) {
   constexpr int kButtonWidth = 32;
-  const int mode = ui::MaterialDesignController::GetMode();
-  switch (size) {
-    case AshLayoutSize::kBrowserCaptionMaximized: {
-      // These constants should be kept in sync with those for TAB_HEIGHT in
-      // chrome/browser/ui/layout_constants.cc.
-      // TODO: Ideally these values should be obtained from a common location.
-      constexpr int kBrowserMaximizedCaptionButtonHeight[] = {29, 33, 41, 34,
-                                                              41};
-      return gfx::Size(kButtonWidth,
-                       kBrowserMaximizedCaptionButtonHeight[mode]);
-    }
-    case AshLayoutSize::kBrowserCaptionRestored: {
-      constexpr int kBrowserRestoredCaptionButtonHeight[] = {36, 40, 48, 41,
-                                                             48};
-      return gfx::Size(kButtonWidth, kBrowserRestoredCaptionButtonHeight[mode]);
-    }
-    case AshLayoutSize::kNonBrowserCaption:
-      return gfx::Size(kButtonWidth, 32);
-  }
 
-  NOTREACHED();
-  return gfx::Size();
+  if (size == AshLayoutSize::kNonBrowserCaption)
+    return gfx::Size(kButtonWidth, 32);
+
+  // |kBrowserMaximizedCaptionButtonHeight| should be kept in sync with those
+  // for TAB_HEIGHT in // chrome/browser/ui/layout_constants.cc.
+  // TODO: Ideally these values should be obtained from a common location.
+  constexpr int kBrowserMaximizedCaptionButtonHeight[] = {29, 33, 41, 34, 41};
+  const int mode = ui::MaterialDesignController::GetMode();
+  int height = kBrowserMaximizedCaptionButtonHeight[mode];
+  if (size == AshLayoutSize::kBrowserCaptionRestored)
+    height += 8;  // Restored window titlebars are 8 DIP taller than maximized.
+  return gfx::Size(kButtonWidth, height);
 }
 
 }  // namespace ash