ManhattanStyle: Fix themed drawing of toolbar extension

The extension image gets queried via QStyle::standardIcon() instead of
QStyle::standardPixmap(). That's why so far our extension was never
drawn with our own icon.

The icon .png needed to be resized in order not to be resampled in @2x
mode.

Change-Id: I27ae4e5872c18421e5d40271b01cb9daf8adc8bc
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/coreplugin/manhattanstyle.cpp

@@ -122,13 +122,13 @@ public:
     void init();
 
 public:
-    const QPixmap extButtonPixmap;
+    const QIcon extButtonIcon;
     const QPixmap closeButtonPixmap;
     StyleAnimator animator;
 };
 
 ManhattanStylePrivate::ManhattanStylePrivate() :
-    extButtonPixmap(Utils::Icons::TOOLBAR_EXTENSION.pixmap()),
+    extButtonIcon(Utils::Icons::TOOLBAR_EXTENSION.icon()),
     closeButtonPixmap(Utils::Icons::CLOSE_FOREGROUND.pixmap())
 {
 }
@@ -321,9 +321,6 @@ QPixmap ManhattanStyle::standardPixmap(StandardPixmap standardPixmap, const QSty
 
     QPixmap pixmap;
     switch (standardPixmap) {
-    case QStyle::SP_ToolBarHorizontalExtensionButton:
-        pixmap = d->extButtonPixmap;
-        break;
     case QStyle::SP_TitleBarCloseButton:
         pixmap = d->closeButtonPixmap;
         break;
@@ -336,7 +333,16 @@ QPixmap ManhattanStyle::standardPixmap(StandardPixmap standardPixmap, const QSty
 
 QIcon ManhattanStyle::standardIcon(StandardPixmap standardIcon, const QStyleOption *option, const QWidget *widget) const
 {
-    QIcon icon = QProxyStyle::standardIcon(standardIcon, option, widget);
+    QIcon icon;
+    switch (standardIcon) {
+    case QStyle::SP_ToolBarHorizontalExtensionButton:
+        icon = d->extButtonIcon;
+        break;
+    default:
+        icon = QProxyStyle::standardIcon(standardIcon, option, widget);
+        break;
+    }
+
     if (standardIcon == QStyle::SP_ComputerIcon) {
         // Ubuntu has in some versions a 16x16 icon, see QTCREATORBUG-12832
         const QList<QSize> &sizes = icon.availableSizes();

src/tools/icons/qtcreatoricons.svg

@@ -156,17 +156,6 @@
        x2="160.5"
        y2="588"
        gradientUnits="userSpaceOnUse" />
-    <clipPath
-       clipPathUnits="userSpaceOnUse"
-       id="clipPath4754">
-      <rect
-         style="fill:none;stroke:none"
-         id="rect4756"
-         width="9"
-         height="9"
-         x="187"
-         y="592" />
-    </clipPath>
     <clipPath
        clipPathUnits="userSpaceOnUse"
        id="clipPath4845">
@@ -4191,15 +4180,14 @@
     </g>
     <g
        id="src/libs/utils/images/extension"
-       style="display:inline;"
-       clip-path="url(#clipPath4754)"
+       style="display:inline"
        transform="translate(-171,-20)">
       <rect
          id="use4527"
          width="9"
-         height="9"
+         height="16"
          x="187"
-         y="592"
+         y="588"
          style="fill:#ffffff" />
       <path
          sodipodi:nodetypes="ccc"