Make IsSolidColor() a property on CC scrollbar layers.

content/browser/android/content_startup_flags.cc

Index: content/browser/android/content_startup_flags.cc
diff --git a/content/browser/android/content_startup_flags.cc b/content/browser/android/content_startup_flags.cc
index 1d959dc368f50db72b4778b0b3acea3206fdf437..f605b67a7f104caa7edf6995dbc1cabcb588b352 100644
--- a/content/browser/android/content_startup_flags.cc
+++ b/content/browser/android/content_startup_flags.cc
@@ -16,6 +16,11 @@
 
 namespace content {
 
+namespace {
+const char kSolidColorScrollbarThicknessValue[] = "=3";
+const char kSolidColorScrollbarColorValue[] = "=0x80808080";
+}  // namespace
+
 void SetContentCommandLineFlags(int max_render_process_count,
                                 const std::string& plugin_descriptor) {
   // May be called multiple times, to cover all possible program entry points.
@@ -61,6 +66,15 @@ void SetContentCommandLineFlags(int max_render_process_count,
   parsed_command_line->AppendSwitch(switches::kEnableGestureTapHighlight);
   parsed_command_line->AppendSwitch(switches::kEnablePinch);
   parsed_command_line->AppendSwitch(switches::kEnableOverscrollNotifications);
+  parsed_command_line->AppendSwitch(cc::switches::kForceSolidColorScrollbars);
+
+  std::string thickness_string(cc::switches::kSolidColorScrollbarThickness);
+  thickness_string.append(kSolidColorScrollbarThicknessValue);
+  parsed_command_line->AppendSwitch(thickness_string);
+
+  std::string color_string(cc::switches::kSolidColorScrollbarColor);
+  color_string.append(kSolidColorScrollbarColorValue);
+  parsed_command_line->AppendSwitch(color_string);
 
   // Run the GPU service as a thread in the browser instead of as a
   // standalone process.