SELECT element: Fix a bug that intrinsic width is too narrow in less-than-100% zoom level.

third_party/WebKit/Source/core/layout/LayoutThemeDefault.cpp

 /*
  * Copyright (C) 2007 Apple Inc.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Collabora Ltd.
  * Copyright (C) 2008, 2009 Google Inc.
  * Copyright (C) 2009 Kenneth Rohde Christiansen
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 10 matching lines @@
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #include "core/layout/LayoutThemeDefault.h"
 
 #include "core/CSSValueKeywords.h"
 #include "core/layout/LayoutThemeFontProvider.h"
 #include "core/paint/MediaControlsPainter.h"
 #include "core/style/ComputedStyle.h"
+#include "platform/HostWindow.h"
 #include "platform/LayoutTestSupport.h"
 #include "platform/PlatformResourceLoader.h"
 #include "platform/graphics/Color.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebThemeEngine.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 // These values all match Safari/Win.
 static const float defaultControlFontPixelSize = 13;
 static const float defaultCancelButtonSize = 9;
 static const float minCancelButtonSize = 5;
 static const float maxCancelButtonSize = 21;
-static const int menuListArrowPaddingSize = 14;
 
 static bool useMockTheme() {
   return LayoutTestSupport::isMockThemeEnabledForTest();
 }
 
 unsigned LayoutThemeDefault::m_activeSelectionBackgroundColor = 0xff1e90ff;
 unsigned LayoutThemeDefault::m_activeSelectionForegroundColor = Color::black;
 unsigned LayoutThemeDefault::m_inactiveSelectionBackgroundColor = 0xffc8c8c8;
 unsigned LayoutThemeDefault::m_inactiveSelectionForegroundColor = 0xff323232;
 
 double LayoutThemeDefault::m_caretBlinkInterval;
 
-LayoutThemeDefault::LayoutThemeDefault() : LayoutTheme(nullptr) {
+LayoutThemeDefault::LayoutThemeDefault()
+    : LayoutTheme(nullptr), m_painter(*this) {
   m_caretBlinkInterval = LayoutTheme::caretBlinkInterval();
 }
 
 LayoutThemeDefault::~LayoutThemeDefault() {}
 
 bool LayoutThemeDefault::themeDrawsFocusRing(const ComputedStyle& style) const {
   if (useMockTheme()) {
     // Don't use focus rings for buttons when mocking controls.
     return style.appearance() == ButtonPart ||
            style.appearance() == PushButtonPart ||
@@ skipping 240 matching lines @@
 
 // The following internal paddings are in addition to the user-supplied padding.
 // Matches the Firefox behavior.
 
 int LayoutThemeDefault::popupInternalPaddingStart(
     const ComputedStyle& style) const {
   return menuListInternalPadding(style, 4);
 }
 
 int LayoutThemeDefault::popupInternalPaddingEnd(
+    const HostWindow* host,
     const ComputedStyle& style) const {
-  return menuListInternalPadding(style, 4 + menuListArrowPaddingSize);
+  if (style.appearance() == NoControlPart)
+    return 0;
+  return 1 * style.effectiveZoom() +
+         clampedMenuListArrowPaddingSize(host, style);
 }
 
 int LayoutThemeDefault::popupInternalPaddingTop(
     const ComputedStyle& style) const {
   return menuListInternalPadding(style, 1);
 }
 
 int LayoutThemeDefault::popupInternalPaddingBottom(
     const ComputedStyle& style) const {
   return menuListInternalPadding(style, 1);
 }
 
 // static
+int LayoutThemeDefault::scrollbarThicknessInDIP() {
+  int width = Platform::current()
+                  ->themeEngine()
+                  ->getSize(WebThemeEngine::PartScrollbarDownArrow)
+                  .width;
+  return width > 0 ? width : 15;
+}
+
+// static
+float LayoutThemeDefault::clampedMenuListArrowPaddingSize(
+    const HostWindow* host,
+    const ComputedStyle& style) {
+  int originalSize = scrollbarThicknessInDIP();
+  int scaledSize =
+      host ? host->windowToViewportScalar(originalSize) : originalSize;
+  // The result should not be samller than the scrollbar thickness in order to
+  // secure space for scrollbar in popup.
+  float deviceScale = 1.0f * scaledSize / originalSize;
+  if (style.effectiveZoom() < deviceScale)
+    return scaledSize;
+  // The value should be zoomed though scrollbars aren't scaled by zoom.
+  // crbug.com/432795.
+  return originalSize * style.effectiveZoom();
+}
+
+// static
 void LayoutThemeDefault::setDefaultFontSize(int fontSize) {
   LayoutThemeFontProvider::setDefaultFontSize(fontSize);
 }
 
 int LayoutThemeDefault::menuListInternalPadding(const ComputedStyle& style,
                                                 int padding) const {
   if (style.appearance() == NoControlPart)
     return 0;
   return padding * style.effectiveZoom();
 }
 
 //
 // Following values are come from default of GTK+
 //
 static const int progressAnimationFrames = 10;
 static const double progressAnimationInterval = 0.125;
 
 double LayoutThemeDefault::animationRepeatIntervalForProgressBar() const {
   return progressAnimationInterval;
 }
 
 double LayoutThemeDefault::animationDurationForProgressBar() const {
   return progressAnimationInterval * progressAnimationFrames *
          2;  // "2" for back and forth
 }
 
 }  // namespace blink