Make IsSolidColor() a property on CC scrollbar layers.

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index f5914f50dfe6bacbe8d932884590825d332e66a9..8d00dfda5c6235f06ac23e4c9143c63dfbec6e2b 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -74,6 +74,22 @@ bool GetSwitchValueAsFloat(
   }
 }
 
+bool StringToSkColor(const std::string& str, SkColor& color) {
+  std::string prefix = str.substr(0,2);
+  int offset = (prefix == "0x" || prefix == "0X") ? 2 : 0;
+
+  std::vector<uint8> values;
+  if (base::HexStringToBytes(str.substr(offset), &values)) {
+    if (values.size() != 4)
+      return false;
+
+    color = SkColorSetARGB(values[0], values[1], values[2], values[3]);
+    return true;
+  }
+
+  return false;
+}
+
 
 }  // namespace
 
@@ -269,12 +285,29 @@ scoped_ptr<RenderWidgetCompositor> RenderWidgetCompositor::Create(
   settings.can_use_lcd_text = false;
   settings.max_partial_texture_updates = 0;
   settings.use_linear_fade_scrollbar_animator = true;
-  settings.solid_color_scrollbars = true;
-  settings.solid_color_scrollbar_color = SkColorSetARGB(128, 128, 128, 128);
-  settings.solid_color_scrollbar_thickness_dip = 3;
   settings.highp_threshold_min = 2048;
 #endif
 
+  if (cmd->HasSwitch(cc::switches::kForceSolidColorScrollbars))
+    settings.force_solid_color_scrollbars = true;
+
+  if (cmd->HasSwitch(cc::switches::kSolidColorScrollbarThickness)) {
+    std::string str =
+        cmd->GetSwitchValueASCII(cc::switches::kSolidColorScrollbarThickness);
+    int thickness;
+    if (base::StringToInt(str, &thickness))
+      settings.solid_color_scrollbar_thickness_dip = std::max(0, thickness);
+  }
+
+  if (cmd->HasSwitch(cc::switches::kSolidColorScrollbarColor)) {
+    std::string str =
+        cmd->GetSwitchValueASCII(cc::switches::kSolidColorScrollbarColor);
+
+    SkColor scrollbar_color;
+    if (StringToSkColor(str, scrollbar_color))
+      settings.solid_color_scrollbar_color = scrollbar_color;
+  }
+
   if (!compositor->initialize(settings))
     return scoped_ptr<RenderWidgetCompositor>();