Remove use_solid_color_scrollbars pref and settings (chrome side)

It didn't work by itself. It was just a redundant information of
whether the scrollbar theme supports solid color scrollbars.

Change-Id: I32c61c8337bb8546a05841723833905463e71457
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1896675Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712458}

content/browser/renderer_host/input/scroll_latency_browsertest.cc

@@ -284,9 +284,9 @@ class ScrollLatencyScrollbarBrowserTest : public ScrollLatencyBrowserTest {
     //    coordinates to manipulate the scrollbar is different from other
     //    platforms.
     // We could overcome the first limitation, by toggling various features
-    // and WebPreferences (e.g. kOverlayScrollbar feature, and
-    // viewport_enabled and use_solid_color_scrollbars WebPreferences) but at
-    // that point, we're not really testing a shipping configuration.
+    // and WebPreferences (e.g. kOverlayScrollbar feature, and viewport_enabled
+    // WebPreferences) but at that point, we're not really testing a shipping
+    // configuration.
 #if !defined(OS_ANDROID)
 
     // Click on the forward scrollbar button to induce a compositor thread

content/browser/renderer_host/render_view_host_impl.cc

@@ -501,16 +501,10 @@ const WebPreferences RenderViewHostImpl::ComputeWebPreferences() {
       atoi(command_line.GetSwitchValueASCII(
       switches::kAcceleratedCanvas2dMSAASampleCount).c_str());
 
-  prefs.use_solid_color_scrollbars = false;
-
   prefs.disable_ipc_flooding_protection =
       command_line.HasSwitch(switches::kDisableIpcFloodingProtection) ||
       command_line.HasSwitch(switches::kDisablePushStateThrottle);
 
-#if defined(OS_ANDROID)
-  prefs.use_solid_color_scrollbars = true;
-#endif  // defined(OS_ANDROID)
-
   prefs.accelerated_video_decode_enabled =
       !command_line.HasSwitch(switches::kDisableAcceleratedVideoDecode);
 

content/public/common/common_param_traits_macros.h

@@ -139,7 +139,6 @@ IPC_STRUCT_TRAITS_BEGIN(content::WebPreferences)
   IPC_STRUCT_TRAITS_MEMBER(webgl2_enabled)
   IPC_STRUCT_TRAITS_MEMBER(pepper_3d_enabled)
   IPC_STRUCT_TRAITS_MEMBER(record_whole_document)
-  IPC_STRUCT_TRAITS_MEMBER(use_solid_color_scrollbars)
   IPC_STRUCT_TRAITS_MEMBER(flash_3d_enabled)
   IPC_STRUCT_TRAITS_MEMBER(flash_stage3d_enabled)
   IPC_STRUCT_TRAITS_MEMBER(flash_stage3d_baseline_enabled)

content/public/common/web_preferences.cc

@@ -164,7 +164,6 @@ WebPreferences::WebPreferences()
 #endif
       spatial_navigation_enabled(false),
       caret_browsing_enabled(false),
-      use_solid_color_scrollbars(false),
       navigate_on_drag_drop(true),
       v8_cache_options(blink::mojom::V8CacheOptions::kDefault),
       record_whole_document(false),

content/public/common/web_preferences.h

@@ -179,7 +179,6 @@ struct CONTENT_EXPORT WebPreferences {
   bool smart_insert_delete_enabled;
   bool spatial_navigation_enabled;
   bool caret_browsing_enabled;
-  bool use_solid_color_scrollbars;
   bool navigate_on_drag_drop;
   blink::mojom::V8CacheOptions v8_cache_options;
   bool record_whole_document;

content/renderer/render_view_impl.cc

@@ -888,8 +888,6 @@ void RenderView::ApplyWebPreferences(const WebPreferences& prefs,
   settings->SetMainFrameResizesAreOrientationChanges(
       prefs.main_frame_resizes_are_orientation_changes);
 
-  settings->SetUseSolidColorScrollbars(prefs.use_solid_color_scrollbars);
-
   settings->SetShowContextMenuOnMouseUp(prefs.context_menu_on_mouse_up);
   settings->SetAlwaysShowContextMenuOnTouch(
       prefs.always_show_context_menu_on_touch);

third_party/blink/public/web/web_settings.h

@@ -260,8 +260,6 @@ class WebSettings {
   virtual void SetBarrelButtonForDragEnabled(bool) = 0;
   virtual void SetUseLegacyBackgroundSizeShorthandBehavior(bool) = 0;
   virtual void SetViewportStyle(WebViewportStyle) = 0;
-  // TODO(wangxianzhu): Remove this function when removing chrome side caller.
-  void SetUseSolidColorScrollbars(bool) {}
   virtual void SetUseWideViewport(bool) = 0;
   virtual void SetV8CacheOptions(V8CacheOptions) = 0;
   virtual void SetValidationMessageTimerMagnification(int) = 0;