Fix the misalignment on CrOS of the tab background images

chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc

Index: chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
diff --git a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
index f8e98273d8facf3b0f05ec2de3abf1f446a660ed..7d16ab570d53e9b7ca2999330fa3d13062852aae 100644
--- a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
+++ b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
@@ -502,23 +502,8 @@ void TabRendererGtk::PaintFaviconArea(GtkWidget* widget, cairo_t* cr) {
   cairo_matrix_init_translate(&cairo_matrix, x(), y());
   cairo_set_matrix(cr, &cairo_matrix);
 
-  // Which background should we be painting?
-  int theme_id;
-  int offset_y = 0;
-  if (IsActive()) {
-    theme_id = IDR_THEME_TOOLBAR;
-  } else {
-    theme_id = data_.incognito ? IDR_THEME_TAB_BACKGROUND_INCOGNITO :
-               IDR_THEME_TAB_BACKGROUND;
-
-    if (!theme_service_->HasCustomImage(theme_id))
-      offset_y = background_offset_y_;
-  }
-
   // Paint the background behind the favicon.
-  const gfx::Image tab_bg = theme_service_->GetImageNamed(theme_id);
-  tab_bg.ToCairo()->SetSource(cr, widget, -x(), -offset_y);
-  cairo_pattern_set_extend(cairo_get_source(cr), CAIRO_EXTEND_REPEAT);
+  SetTabBackgroundImageAsSource(cr, widget, favicon_bounds_);
   cairo_rectangle(cr,
                   favicon_bounds_.x(), favicon_bounds_.y(),
                   favicon_bounds_.width(), favicon_bounds_.height());
@@ -957,17 +942,6 @@ void TabRendererGtk::PaintIcon(GtkWidget* widget, cairo_t* cr) {
       cairo_paint(cr);
     } else if (data_.capture_state == RECORDING) {
       // Add mask around the recording overlay image (red dot).
-      gfx::CairoCachedSurface* tab_bg;
-      if (IsActive()) {
-        tab_bg = theme_service_->GetImageNamed(IDR_THEME_TOOLBAR).ToCairo();
-      } else {
-        int theme_id = data_.incognito ?
-          IDR_THEME_TAB_BACKGROUND_INCOGNITO : IDR_THEME_TAB_BACKGROUND;
-        tab_bg = theme_service_->GetImageNamed(theme_id).ToCairo();
-      }
-      tab_bg->SetSource(cr, widget, -background_offset_x_, 0);
-      cairo_pattern_set_extend(cairo_get_source(cr), CAIRO_EXTEND_REPEAT);
-
       gfx::CairoCachedSurface* recording_mask =
           theme_service_->GetImageNamed(IDR_TAB_RECORDING_MASK).ToCairo();
       int offset_from_right = data_.cairo_overlay.Width() +
@@ -978,6 +952,9 @@ void TabRendererGtk::PaintIcon(GtkWidget* widget, cairo_t* cr) {
           (recording_mask->Height() - data_.cairo_overlay.Height()) / 2;
       int favicon_y = favicon_bounds_.y() + favicon_hiding_offset_ +
           favicon_bounds_.height() - offset_from_bottom;
+      SetTabBackgroundImageAsSource(cr, widget,
+          gfx::Rect(favicon_x, favicon_y, recording_mask->Width(),
+                    recording_mask->Height()));
       recording_mask->MaskSource(cr, widget, favicon_x, favicon_y);
 
       if (!IsActive()) {
@@ -1026,15 +1003,56 @@ void TabRendererGtk::PaintTabBackground(GtkWidget* widget, cairo_t* cr) {
   }
 }
 
-void TabRendererGtk::DrawTabBackground(
-    cairo_t* cr,
-    GtkWidget* widget,
-    const gfx::Image& tab_bg,
-    int offset_x,
-    int offset_y) {
-  tab_bg.ToCairo()->SetSource(cr, widget, -offset_x, -offset_y);
+void TabRendererGtk::SetTabBackgroundImageAsSource(cairo_t* cr,
+                                                   GtkWidget* widget,
+                                                   const gfx::Rect& bounds) {
+  int tab_bg_id = 0;
+  int tab_bg_offset_y = 0;
+  int tab_bg_overlay_id = 0;
+  if (IsActive()) {
+    tab_bg_id = IDR_THEME_TOOLBAR;
+
+    // The image at |tab_bg_id| is aligned with the top of the tab.
+    tab_bg_offset_y = 0;
+  } else {
+    tab_bg_id = data_.incognito ? IDR_THEME_TAB_BACKGROUND_INCOGNITO :
+        IDR_THEME_TAB_BACKGROUND;
+    // |tab_bg_id| is the tinted frame image. Set |tab_bg_offset_y_| so that
+    // the image is aligned with the top of the frame.
+    tab_bg_offset_y = background_offset_y_;
+
+    tab_bg_overlay_id = data_.incognito ?
+        IDR_THEME_TAB_BACKGROUND_INCOGNITO_OVERLAY :
+        IDR_THEME_TAB_BACKGROUND_OVERLAY;
+  }
+  gfx::Image tab_bg = theme_service_->GetImageNamed(tab_bg_id);
+  tab_bg.ToCairo()->SetSource(cr, widget, -background_offset_x_,
+      -tab_bg_offset_y);
   cairo_pattern_set_extend(cairo_get_source(cr), CAIRO_EXTEND_REPEAT);
 
+  // The default theme does not provide overlay images.
+  if (tab_bg_overlay_id != 0 &&
+      theme_service_->HasCustomImage(tab_bg_overlay_id)) {
+    cairo_push_group(cr);
+    cairo_rectangle(cr, bounds.x(), bounds.y(), bounds.width(),
+        bounds.height());
+    cairo_fill_preserve(cr);
+
+    gfx::Image tab_bg_overlay =
+        theme_service_->GetImageNamed(tab_bg_overlay_id);
+    // |tab_bg_overlay| is aligned with the top of the tab.
+    tab_bg_overlay.ToCairo()->SetSource(cr, widget, -background_offset_x_, 0);
+    cairo_pattern_set_extend(cairo_get_source(cr), CAIRO_EXTEND_REPEAT);
+    cairo_fill(cr);
+
+    cairo_pop_group_to_source(cr);
+  }
+}
+
+void TabRendererGtk::DrawTabBackground(cairo_t* cr, GtkWidget* widget) {
+  SetTabBackgroundImageAsSource(cr, widget,
+      gfx::Rect(0, 0, width(), tab_inactive_l_height_));
+
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
 
   // Draw left edge
@@ -1084,28 +1102,14 @@ void TabRendererGtk::DrawTabShadow(cairo_t* cr,
 
 void TabRendererGtk::PaintInactiveTabBackground(GtkWidget* widget,
                                                 cairo_t* cr) {
-  int theme_id = data_.incognito ?
-      IDR_THEME_TAB_BACKGROUND_INCOGNITO : IDR_THEME_TAB_BACKGROUND;
-
-  gfx::Image tab_bg = theme_service_->GetImageNamed(theme_id);
-
-  // If the theme is providing a custom background image, then its top edge
-  // should be at the top of the tab. Otherwise, we assume that the background
-  // image is a composited foreground + frame image.
-  int offset_y = theme_service_->HasCustomImage(theme_id) ?
-      0 : background_offset_y_;
-
-  DrawTabBackground(cr, widget, tab_bg, background_offset_x_, offset_y);
-
+  DrawTabBackground(cr, widget);
   DrawTabShadow(cr, widget, IDR_TAB_INACTIVE_LEFT, IDR_TAB_INACTIVE_CENTER,
                 IDR_TAB_INACTIVE_RIGHT);
 }
 
 void TabRendererGtk::PaintActiveTabBackground(GtkWidget* widget,
                                               cairo_t* cr) {
-  gfx::Image tab_bg = theme_service_->GetImageNamed(IDR_THEME_TOOLBAR);
-
-  DrawTabBackground(cr, widget, tab_bg, background_offset_x_, 0);
+  DrawTabBackground(cr, widget);
   DrawTabShadow(cr, widget, IDR_TAB_ACTIVE_LEFT, IDR_TAB_ACTIVE_CENTER,
                 IDR_TAB_ACTIVE_RIGHT);
 }