From 2ece85392855af0ea2c9406f98922a869d335bcd Mon Sep 17 00:00:00 2001
From: Milan Burda <milan.burda@gmail.com>
Date: Thu, 20 Sep 2018 17:47:01 -0700
Subject: webgl_context_attributes.patch


diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index a9b86c68fe50..46931503ec2b 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -997,8 +997,10 @@ RendererBlinkPlatformImpl::CreateOffscreenGraphicsContext3DProvider(
   attributes.sample_buffers = 0;
   attributes.bind_generates_resource = false;
   attributes.enable_raster_interface = web_attributes.enable_raster_interface;
-  // Prefer discrete GPU for WebGL.
-  attributes.gpu_preference = gl::PreferDiscreteGpu;
+
+  attributes.gpu_preference = web_attributes.prefer_integrated_gpu
+      ? gl::PreferIntegratedGpu
+      : gl::PreferDiscreteGpu;
 
   attributes.fail_if_major_perf_caveat =
       web_attributes.fail_if_major_performance_caveat;
diff --git a/third_party/blink/public/platform/platform.h b/third_party/blink/public/platform/platform.h
index f927253a7e0b..12ada20ec3a3 100644
--- a/third_party/blink/public/platform/platform.h
+++ b/third_party/blink/public/platform/platform.h
@@ -500,6 +500,7 @@ class BLINK_PLATFORM_EXPORT Platform {
     kGLES3ContextType,  // GLES 3.0 context
   };
   struct ContextAttributes {
+    bool prefer_integrated_gpu = false;
     bool fail_if_major_performance_caveat = false;
     ContextType context_type = kGLES2ContextType;
     // Offscreen contexts usually share a surface for the default frame buffer
diff --git a/third_party/blink/renderer/core/html/canvas/canvas_context_creation_attributes_core.h b/third_party/blink/renderer/core/html/canvas/canvas_context_creation_attributes_core.h
index 03da0840b0e3..9551675de44d 100644
--- a/third_party/blink/renderer/core/html/canvas/canvas_context_creation_attributes_core.h
+++ b/third_party/blink/renderer/core/html/canvas/canvas_context_creation_attributes_core.h
@@ -30,6 +30,7 @@ class CORE_EXPORT CanvasContextCreationAttributesCore {
   String pixel_format = "8-8-8-8";
   bool premultiplied_alpha = true;
   bool preserve_drawing_buffer = false;
+  String power_preference = "default";
   bool stencil = false;
 
   // This attribute is of type XRDevice, defined in modules/xr/XRDevice.h
diff --git a/third_party/blink/renderer/modules/canvas/htmlcanvas/canvas_context_creation_attributes_module.idl b/third_party/blink/renderer/modules/canvas/htmlcanvas/canvas_context_creation_attributes_module.idl
index 7b655dd12a77..8969eb7d98f3 100644
--- a/third_party/blink/renderer/modules/canvas/htmlcanvas/canvas_context_creation_attributes_module.idl
+++ b/third_party/blink/renderer/modules/canvas/htmlcanvas/canvas_context_creation_attributes_module.idl
@@ -28,6 +28,12 @@ enum CanvasPixelFormat {
     "float16",
 };
 
+enum CanvasPowerPreference {
+    "default",
+    "low-power",
+    "high-performance",
+};
+
 [PermissiveDictionaryConversion]
 dictionary CanvasContextCreationAttributesModule {
     // This is an experimental feature, but it is not hidden behind a flag in
@@ -47,6 +53,7 @@ dictionary CanvasContextCreationAttributesModule {
     boolean antialias = true;
     boolean premultipliedAlpha = true;
     boolean preserveDrawingBuffer = false;
+    CanvasPowerPreference powerPreference = "default";
     boolean failIfMajorPerformanceCaveat = false;
     [OriginTrialEnabled=WebXR] XRDevice compatibleXRDevice = null;
 };
diff --git a/third_party/blink/renderer/modules/webgl/webgl_context_attribute_helpers.cc b/third_party/blink/renderer/modules/webgl/webgl_context_attribute_helpers.cc
index 3846b2a179d9..bf7c63a81391 100644
--- a/third_party/blink/renderer/modules/webgl/webgl_context_attribute_helpers.cc
+++ b/third_party/blink/renderer/modules/webgl/webgl_context_attribute_helpers.cc
@@ -18,6 +18,7 @@ WebGLContextAttributes ToWebGLContextAttributes(
   result.setAntialias(attrs.antialias);
   result.setPremultipliedAlpha(attrs.premultiplied_alpha);
   result.setPreserveDrawingBuffer(attrs.preserve_drawing_buffer);
+  result.setPowerPreference(attrs.power_preference);
   result.setFailIfMajorPerformanceCaveat(
       attrs.fail_if_major_performance_caveat);
   result.setCompatibleXRDevice(
@@ -30,6 +31,7 @@ Platform::ContextAttributes ToPlatformContextAttributes(
     Platform::ContextType context_type,
     bool support_own_offscreen_surface) {
   Platform::ContextAttributes result;
+  result.prefer_integrated_gpu = attrs.power_preference == "low-power";
   result.fail_if_major_performance_caveat =
       attrs.fail_if_major_performance_caveat;
   result.context_type = context_type;
diff --git a/third_party/blink/renderer/modules/webgl/webgl_context_attributes.idl b/third_party/blink/renderer/modules/webgl/webgl_context_attributes.idl
index 38ca0f6b6a0c..90cfe8497daf 100644
--- a/third_party/blink/renderer/modules/webgl/webgl_context_attributes.idl
+++ b/third_party/blink/renderer/modules/webgl/webgl_context_attributes.idl
@@ -26,6 +26,12 @@
 
 // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.2
 
+enum WebGLPowerPreference {
+    "default",
+    "low-power",
+    "high-performance",
+};
+
 dictionary WebGLContextAttributes {
     boolean alpha = true;
     boolean depth = true;
@@ -33,6 +39,7 @@ dictionary WebGLContextAttributes {
     boolean antialias = true;
     boolean premultipliedAlpha = true;
     boolean preserveDrawingBuffer = false;
+    WebGLPowerPreference powerPreference = "default";
     boolean failIfMajorPerformanceCaveat = false;
     [OriginTrialEnabled=WebXR] XRDevice compatibleXRDevice = null;
 };
-- 
2.17.0