Bug 1523728 - Add gl.allow-high-power:true, webgl.default-low-power:false. r=lsalzman

Also, if "Use hardware acceleration when available" is disabled, restrict webgl to the igpu.

Differential Revision: https://phabricator.services.mozilla.com/D19059

--HG--
extra : moz-landing-system : lando

dom/canvas/WebGLContext.cpp

@@ -9,6 +9,7 @@
 #include <queue>
 
 #include "AccessCheck.h"
+#include "gfxConfig.h"
 #include "gfxContext.h"
 #include "gfxCrashReporterUtils.h"
 #include "gfxPattern.h"
@@ -483,6 +484,10 @@ bool WebGLContext::CreateAndInitGL(
     case dom::WebGLPowerPreference::Low_power:
       break;
 
+    case dom::WebGLPowerPreference::High_performance:
+      flags |= gl::CreateContextFlags::HIGH_POWER;
+      break;
+
       // Eventually add a heuristic, but for now default to high-performance.
       // We can even make it dynamic by holding on to a
       // ForceDiscreteGPUHelperCGL iff we decide it's a high-performance
@@ -491,12 +496,18 @@ bool WebGLContext::CreateAndInitGL(
       // - Many draw calls
       // - Same origin with root page (try to stem bleeding from WebGL
       // ads/trackers)
-    case dom::WebGLPowerPreference::High_performance:
     default:
-      flags |= gl::CreateContextFlags::HIGH_POWER;
+      if (!gfxPrefs::WebGLDefaultLowPower()) {
+        flags |= gl::CreateContextFlags::HIGH_POWER;
+      }
       break;
   }
 
+  // If "Use hardware acceleration when available" option is disabled:
+  if (!gfxConfig::IsEnabled(Feature::HW_COMPOSITING)) {
+    flags &= ~gl::CreateContextFlags::HIGH_POWER;
+  }
+
 #ifdef XP_MACOSX
   const nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
   nsString vendorID, deviceID;

gfx/gl/GLContextProviderCGL.mm

@@ -225,6 +225,9 @@ static already_AddRefed<GLContextCGL> CreateOffscreenFBOContext(CreateContextFla
 
   std::vector<NSOpenGLPixelFormatAttribute> attribs;
 
+  if (!gfxPrefs::GLAllowHighPower()) {
+    flags &= ~CreateContextFlags::HIGH_POWER;
+  }
   if (flags & CreateContextFlags::ALLOW_OFFLINE_RENDERER ||
       !(flags & CreateContextFlags::HIGH_POWER)) {
     // This is really poorly named on Apple's part, but "AllowOfflineRenderers" means

gfx/thebes/gfxPrefs.h

@@ -558,6 +558,7 @@ class gfxPrefs final {
   // Use vsync events generated by hardware
   DECL_GFX_PREF(Once, "gfx.work-around-driver-bugs",           WorkAroundDriverBugs, bool, true);
 
+  DECL_GFX_PREF(Live, "gl.allow-high-power",                   GLAllowHighPower, bool, true);
   DECL_GFX_PREF(Live, "gl.ignore-dx-interop2-blacklist",       IgnoreDXInterop2Blacklist, bool, false);
   DECL_GFX_PREF(Live, "gl.msaa-level",                         MSAALevel, uint32_t, 2);
 #if defined(XP_MACOSX)
@@ -595,6 +596,8 @@ class gfxPrefs final {
   DECL_GFX_PREF(Live, "image.webp.enabled",                    ImageWebPEnabled, bool, false);
 
   DECL_GFX_PREF(Once, "layers.acceleration.disabled",          LayersAccelerationDisabledDoNotUseDirectly, bool, false);
+  // Instead, use gfxConfig::IsEnabled(Feature::HW_COMPOSITING).
+
   DECL_GFX_PREF(Live, "layers.acceleration.draw-fps",          LayersDrawFPS, bool, false);
   DECL_GFX_PREF(Live, "layers.acceleration.draw-fps.print-histogram",  FPSPrintHistogram, bool, false);
   DECL_GFX_PREF(Live, "layers.acceleration.draw-fps.write-to-file", WriteFPSToFile, bool, false);
@@ -790,6 +793,7 @@ class gfxPrefs final {
   DECL_GFX_PREF(Live, "webgl.angle.force-warp",                WebGLANGLEForceWARP, bool, false);
   DECL_GFX_PREF(Live, "webgl.bypass-shader-validation",        WebGLBypassShaderValidator, bool, true);
   DECL_GFX_PREF(Live, "webgl.can-lose-context-in-foreground",  WebGLCanLoseContextInForeground, bool, true);
+  DECL_GFX_PREF(Live, "webgl.default-low-power",               WebGLDefaultLowPower, bool, false);
   DECL_GFX_PREF(Live, "webgl.default-no-alpha",                WebGLDefaultNoAlpha, bool, false);
   DECL_GFX_PREF(Live, "webgl.disable-angle",                   WebGLDisableANGLE, bool, false);
   DECL_GFX_PREF(Live, "webgl.disable-wgl",                     WebGLDisableWGL, bool, false);

modules/libpref/init/all.js

@@ -4836,6 +4836,7 @@ pref("gl.multithreaded", true);
 #endif
 pref("gl.ignore-dx-interop2-blacklist", false);
 pref("gl.use-tls-is-current", 0);
+pref("gl.allow-high-power", true);
 
 #ifdef XP_MACOSX
 pref("webgl.1.allow-core-profiles", true);
@@ -4850,6 +4851,7 @@ pref("webgl.min_capability_mode", false);
 pref("webgl.disable-extensions", false);
 pref("webgl.msaa-force", false);
 pref("webgl.prefer-16bpp", false);
+pref("webgl.default-low-power", false);
 pref("webgl.default-no-alpha", false);
 pref("webgl.force-layers-readback", false);
 pref("webgl.force-index-validation", 0);