Gtk3: Bugfixes on several themes

chrome/browser/ui/libgtkui/gtk_util.cc

 // Copyright (c) 2012 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/libgtkui/gtk_util.h"
 
 #include <dlfcn.h>
 #include <gdk/gdk.h>
 #include <gdk/gdkx.h>
 #include <gtk/gtk.h>
@@ skipping 210 matching lines @@
                                           size.width(),
                                           size.height())),
       cairo_(cairo_create(surface_)) {}
 
 CairoSurface::~CairoSurface() {
   cairo_destroy(cairo_);
   cairo_surface_destroy(surface_);
 }
 
 SkColor CairoSurface::GetAveragePixelValue(bool only_frame_pixels) {
+  cairo_surface_flush(surface_);
   int num_samples = 0;
   long a = 0, r = 0, g = 0, b = 0;
   SkColor* data =
       reinterpret_cast<SkColor*>(cairo_image_surface_get_data(surface_));
   int width = cairo_image_surface_get_width(surface_);
   int height = cairo_image_surface_get_height(surface_);
+  DCHECK(4 * width == cairo_image_surface_get_stride(surface_));
   auto accumulate = [&](int x, int y) mutable {
-    SkColor color = data[x * width + y];
+    SkColor color = data[y * width + x];
     int alpha = SkColorGetA(color);
     a += alpha;
     r += alpha * SkColorGetR(color);
     g += alpha * SkColorGetG(color);
     b += alpha * SkColorGetB(color);
     num_samples++;
   };
   if (width == 1 || height == 1 || !only_frame_pixels) {
     // Count every pixel in the surface.
     for (int x = 0; x < width; x++)
       for (int y = 0; y < height; y++)
         accumulate(x, y);
   } else {
     // Count the pixels in the top and bottom rows.
     for (int x = 0; x < width; x++)
       for (int y : {0, height - 1})
         accumulate(x, y);
     // Count the pixels in the left and right columns.
     for (int x : {0, width - 1})
       for (int y = 1; y < height - 1; y++)
         accumulate(x, y);
   }
+  if (a == 0)
+    return SK_ColorTRANSPARENT;
   return SkColorSetARGB(a / num_samples, r / a, g / a, b / a);
 }
 
 bool GtkVersionCheck(int major, int minor, int micro) {
   static int actual_major = gtk_get_major_version();
   if (actual_major > major)
     return true;
   else if (actual_major < major)
     return false;
 
@@ skipping 254 matching lines @@
   // background color.  Only return the border color if there is one.
   SkColor border = GetBorderColor(css_selector);
   if (SkColorGetA(border))
     return border;
 
   return GetBgColor(css_selector);
 }
 #endif
 
 }  // namespace libgtkui