Bug 1414714 - Part 2: Remove unused gfx.* prefs. r=nical

The following prefs are removed because they are defined in gfxPrefs, but the
resulting gfxPrefs property is used at all.
* gfx.SurfaceTexture.detach.enabled
* gfx.touch.resample.*
* gfx.screen-mirroring.enabled

MozReview-Commit-ID: CyI3JN4TTu5

gfx/thebes/gfxPrefs.h

@@ -480,7 +480,6 @@ private:
   DECL_GFX_PREF(Once, "gfx.max-texture-size",                  MaxTextureSizeDoNotUseDirectly, int32_t, (int32_t)32767);
   DECL_GFX_PREF(Live, "gfx.partialpresent.force",              PartialPresent, int32_t, 0);
   DECL_GFX_PREF(Live, "gfx.perf-warnings.enabled",             PerfWarnings, bool, false);
-  DECL_GFX_PREF(Live, "gfx.SurfaceTexture.detach.enabled",     SurfaceTextureDetachEnabled, bool, true);
   DECL_GFX_PREF(Live, "gfx.testing.device-reset",              DeviceResetForTesting, int32_t, 0);
   DECL_GFX_PREF(Live, "gfx.testing.device-fail",               DeviceFailForTesting, bool, false);
   DECL_GFX_PREF(Once, "gfx.text.disable-aa",                   DisableAllTextAA, bool, false);
@@ -492,12 +491,6 @@ private:
   DECL_GFX_PREF(Once, "gfx.use-iosurface-textures",            UseIOSurfaceTextures, bool, false);
   DECL_GFX_PREF(Once, "gfx.use-mutex-on-present",              UseMutexOnPresent, bool, false);
   DECL_GFX_PREF(Once, "gfx.use-surfacetexture-textures",       UseSurfaceTextureTextures, bool, false);
-  // These times should be in milliseconds
-  DECL_GFX_PREF(Once, "gfx.touch.resample.delay-threshold",    TouchResampleVsyncDelayThreshold, int32_t, 20);
-  DECL_GFX_PREF(Once, "gfx.touch.resample.max-predict",        TouchResampleMaxPredict, int32_t, 8);
-  DECL_GFX_PREF(Once, "gfx.touch.resample.min-delta",          TouchResampleMinDelta, int32_t, 2);
-  DECL_GFX_PREF(Once, "gfx.touch.resample.old-touch-threshold",TouchResampleOldTouchThreshold, int32_t, 17);
-  DECL_GFX_PREF(Once, "gfx.touch.resample.vsync-adjust",       TouchVsyncSampleAdjust, int32_t, 5);
 
   DECL_GFX_PREF(Live, "gfx.vsync.collect-scroll-transforms",   CollectScrollTransforms, bool, false);
   DECL_GFX_PREF(Once, "gfx.vsync.compositor.unobserve-count",  CompositorUnobserveCount, int32_t, 10);
@@ -507,7 +500,6 @@ private:
 
   // Use vsync events generated by hardware
   DECL_GFX_PREF(Once, "gfx.work-around-driver-bugs",           WorkAroundDriverBugs, bool, true);
-  DECL_GFX_PREF(Once, "gfx.screen-mirroring.enabled",          ScreenMirroringEnabled, bool, false);
 
   DECL_GFX_PREF(Live, "gl.ignore-dx-interop2-blacklist",       IgnoreDXInterop2Blacklist, bool, false);
   DECL_GFX_PREF(Live, "gl.msaa-level",                         MSAALevel, uint32_t, 2);

mobile/android/app/mobile.js

@@ -330,9 +330,6 @@ pref("gfx.displayport.strategy_pb.threshold", -1); // velocity threshold in inch
 // Allow 24-bit colour when the hardware supports it
 pref("gfx.android.rgb16.force", false);
 
-// Allow GLContexts to be attached/detached from SurfaceTextures
-pref("gfx.SurfaceTexture.detach.enabled", true);
-
 // Use SurfaceTextures as preferred backend for TextureClient/Host
 pref("gfx.use-surfacetexture-textures", false);