Fix regression in dark mode filter creation.

There is regression caused by creating dark mode filter in
GraphicsContext ctor. This patch creates dark mode filter
once it is accessed first time.

Bug: 1134430, 1134476, 1082339
Change-Id: I97521749167fcd1fb7ddfeb1b2fe7e8a7de8846f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2449829Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Prashant Nevase <prashant.n@samsung.com>
Cr-Commit-Position: refs/heads/master@{#813730}

third_party/blink/renderer/platform/graphics/graphics_context.cc

@@ -130,6 +130,7 @@ GraphicsContext::GraphicsContext(PaintController& paint_controller,
       disable_destruction_checks_(false),
 #endif
       device_scale_factor_(1.0f),
+      dark_mode_filter_(nullptr),
       printing_(false),
       is_painting_preview_(false),
       in_drawing_recorder_(false),
@@ -138,9 +139,6 @@ GraphicsContext::GraphicsContext(PaintController& paint_controller,
   // allocate several here.
   paint_state_stack_.push_back(std::make_unique<GraphicsContextState>());
   paint_state_ = paint_state_stack_.back().get();
-
-  dark_mode_filter_ = std::make_unique<DarkModeFilter>();
-  dark_mode_filter_->UpdateSettings(GetCurrentDarkModeSettings());
 }
 
 GraphicsContext::~GraphicsContext() {
@@ -154,6 +152,15 @@ GraphicsContext::~GraphicsContext() {
 #endif
 }
 
+DarkModeFilter* GraphicsContext::GetDarkModeFilter() {
+  if (!dark_mode_filter_) {
+    dark_mode_filter_ = std::make_unique<DarkModeFilter>();
+    dark_mode_filter_->UpdateSettings(GetCurrentDarkModeSettings());
+  }
+
+  return dark_mode_filter_.get();
+}
+
 void GraphicsContext::UpdateDarkModeSettingsForTest(
     const DarkModeSettings& settings) {
   GetDarkModeFilter()->UpdateSettings(settings);

third_party/blink/renderer/platform/graphics/graphics_context.h

@@ -88,7 +88,7 @@ class PLATFORM_EXPORT GraphicsContext {
   bool IsDarkModeEnabled() const { return is_dark_mode_enabled_; }
   void SetDarkModeEnabled(bool enabled) { is_dark_mode_enabled_ = enabled; }
 
-  DarkModeFilter* GetDarkModeFilter() { return dark_mode_filter_.get(); }
+  DarkModeFilter* GetDarkModeFilter();
 
   void UpdateDarkModeSettingsForTest(const DarkModeSettings&);