Modifies logic for computing drop down menu arrow's dimensions and how it is drawn.

components/test_runner/mock_web_theme_engine.cc

 // Copyright 2014 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 "components/test_runner/mock_web_theme_engine.h"
 
 #if !defined(OS_MACOSX)
 
 #include "base/logging.h"
 #include "build/build_config.h"
@@ skipping 464 matching lines @@
       if (extraParams->menuList.fillContentArea) {
         box(canvas, irect, extraParams->menuList.backgroundColor);
       } else {
         SkPaint paint;
         paint.setColor(edgeColor);
         paint.setStyle(SkPaint::kStroke_Style);
         canvas->drawIRect(irect, paint);
       }
 
       // clip the drop-down arrow to be inside the select box
-      if (extraParams->menuList.arrowX - 4 > irect.fLeft)
-        irect.fLeft = extraParams->menuList.arrowX - 4;
-      if (extraParams->menuList.arrowX + 12 < irect.fRight)
-        irect.fRight = extraParams->menuList.arrowX + 12;
+      irect.fLeft =
+          std::max(irect.fLeft, extraParams->menuList.arrowX -
+                                    (extraParams->menuList.arrowSize + 1) / 2);
+      irect.fRight =
+          std::min(irect.fLeft + extraParams->menuList.arrowSize, irect.fRight);
 
       irect.fTop = extraParams->menuList.arrowY -
                    (extraParams->menuList.arrowSize) / 2;
-      irect.fBottom = extraParams->menuList.arrowY +
-                      (extraParams->menuList.arrowSize - 1) / 2;
+      irect.fBottom = irect.fTop + (extraParams->menuList.arrowSize);
+
       halfWidth = irect.width() / 2;
       quarterWidth = irect.width() / 4;
 
       if (state == WebThemeEngine::StateFocused)  // FIXME: draw differenty?
         state = WebThemeEngine::StateNormal;
       box(canvas, irect, bgColors(state));
-      triangle(canvas, irect.fLeft + quarterWidth, irect.fTop,
-               irect.fRight - quarterWidth, irect.fTop, irect.fLeft + halfWidth,
-               irect.fBottom, edgeColor);
+      triangle(canvas, irect.fLeft + quarterWidth, irect.fTop + quarterWidth,
+               irect.fRight - quarterWidth, irect.fTop + quarterWidth,
+               irect.fLeft + halfWidth, irect.fBottom - quarterWidth,
+               edgeColor);
 
       break;
 
     case WebThemeEngine::PartSliderTrack: {
       SkIRect lirect = irect;
 
       // Draw a narrow rect for the track plus box hatches on the ends.
       if (state == WebThemeEngine::StateFocused)  // FIXME: draw differently?
         state = WebThemeEngine::StateNormal;
       if (extraParams->slider.vertical) {
@@ skipping 75 matching lines @@
       // part?
       // Unfortunately, we can't assert because we don't have access to WTF or
       // base.
       break;
   }
 }
 
 }  // namespace test_runner
 
 #endif  // !defined(OS_MACOSX)