[Refactor] Move code for painting the window header for browser windows out of ash

ash/wm/header_metrics.cc

+#include "ash/wm/header_metrics.h"

[James Cook, 2014/03/10 17:32:30]

needs copyright

+
+#include <algorithm>
+
+#include "ui/gfx/font_list.h"
+#include "ui/gfx/rect.h"
+#include "ui/views/view.h"
+
+namespace {
+
+// Radius of the header's top corners when the window is restored.
+const int kTopCornerRadiusWhenRestored = 2;
+
+// Distance between left edge of the window and the header icon.
+const int kIconXOffset = 9;
+
+// Height and width of header icon.
+const int kIconSize = 16;
+
+// Space between the title text and the caption buttons.
+const int kTitleLogoSpacing = 5;
+
+// Space between window icon and title text.
+const int kTitleIconOffsetX = 5;
+
+// Space between window edge and title text, when there is no icon.
+const int kTitleNoIconOffsetX = 8;
+
+// In the pre-Ash era the web content area had a frame along the left edge, so
+// user-generated theme images for the new tab page assume they are shifted
+// right relative to the header.  Now that we have removed the left edge frame
+// we need to copy the theme image for the window header from a few pixels
+// inset to preserve alignment with the NTP image, or else we'll break a bunch
+// of existing themes.  We do something similar on OS X for the same reason.
+const int kThemeFrameImageInsetX = 5;
+
+}  // namespace
+
+namespace ash {
+
+// static
+int HeaderMetrics::GetTopCornerRadiusWhenRestored() {
+  return kTopCornerRadiusWhenRestored;

[James Cook, 2014/03/10 17:32:30]

Optional: Any particular reason these are returned by function calls rather than
just having constants?  I could see this whole class replaced with a namespace
"header_metrics" and these being constants.

[pkotwicz, 2014/03/14 17:56:22]

Given that this class is now HeaderPainterUtil, I am not sure if your suggestion
still makes sense? (I presume your suggestion is to have both HeaderPainterUtil
and a constant only .h file) I want to avoid having too many header painting
related classes

+}
+
+// static
+int HeaderMetrics::GetIconXOffset() {
+  return kIconXOffset;
+}
+
+// static
+int HeaderMetrics::GetIconSize() {
+  return kIconSize;
+}
+
+// static
+gfx::Rect HeaderMetrics::GetTitleBounds(
+    const views::View* icon,
+    const views::View* caption_button_container,
+    const gfx::FontList& title_font_list) {
+  int x = icon ?
+      icon->bounds().right() + kTitleIconOffsetX : kTitleNoIconOffsetX;
+  int height = title_font_list.GetHeight();
+  int y = std::max(
+      0,
+      static_cast<int>(std::ceil(
+          (caption_button_container->height() - height) / 2.0f)));
+  int width = std::max(0,
+                       caption_button_container->x() - kTitleLogoSpacing - x);
+  return gfx::Rect(x, y, width, height);
+}
+
+// static
+int HeaderMetrics::GetThemeBackgroundXInset() {
+  return kThemeFrameImageInsetX;
+}
+
+}  // namespace ash