--- a/configure.in
+++ b/configure.in
@@ -6730,17 +6730,22 @@ dnl ====================================
 MOZ_ARG_ENABLE_BOOL(mobile-optimize,
 [  --enable-mobile-optimize
                           Enable mobile optimizations],
     MOZ_GFX_OPTIMIZE_MOBILE=1)
 
 AC_SUBST(MOZ_GFX_OPTIMIZE_MOBILE)
 
 if test "$MOZ_GFX_OPTIMIZE_MOBILE"; then
+    # We ignore paint will resample on mobile for performance.
+    # We may want to revisit this later.
+    MOZ_IGNORE_PAINT_WILL_RESAMPLE=1
+
     AC_DEFINE(MOZ_GFX_OPTIMIZE_MOBILE)
+    AC_DEFINE(MOZ_IGNORE_PAINT_WILL_RESAMPLE)
 fi
 
 dnl ========================================================
 dnl = Enable code optimization. ON by default.
 dnl ========================================================
 if test -z "$MOZ_OPTIMIZE_FLAGS"; then
     MOZ_OPTIMIZE_FLAGS="-O"
 fi

--- a/gfx/layers/client/ClientThebesLayer.cpp
+++ b/gfx/layers/client/ClientThebesLayer.cpp
@@ -36,17 +36,17 @@ ClientThebesLayer::PaintThebes()
 {
   PROFILER_LABEL("ClientThebesLayer", "PaintThebes",
     js::ProfileEntry::Category::GRAPHICS);
 
   NS_ASSERTION(ClientManager()->InDrawing(),
                "Can only draw in drawing phase");
   
   uint32_t flags = RotatedContentBuffer::PAINT_CAN_DRAW_ROTATED;
-#ifndef MOZ_WIDGET_ANDROID
+#ifndef MOZ_IGNORE_PAINT_WILL_RESAMPLE
   if (ClientManager()->CompositorMightResample()) {
     flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
   }
   if (!(flags & RotatedContentBuffer::PAINT_WILL_RESAMPLE)) {
     if (MayResample()) {
       flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
     }
   }

--- a/gfx/layers/client/ClientTiledThebesLayer.cpp
+++ b/gfx/layers/client/ClientTiledThebesLayer.cpp
@@ -342,17 +342,17 @@ ClientTiledThebesLayer::RenderLayer()
     mContentClient->mTiledBuffer.ResetPaintedAndValidState();
   }
 
   TILING_LOG("TILING %p: Initial visible region %s\n", this, Stringify(mVisibleRegion).c_str());
   TILING_LOG("TILING %p: Initial valid region %s\n", this, Stringify(mValidRegion).c_str());
   TILING_LOG("TILING %p: Initial low-precision valid region %s\n", this, Stringify(mLowPrecisionValidRegion).c_str());
 
   nsIntRegion neededRegion = mVisibleRegion;
-#ifndef MOZ_GFX_OPTIMIZE_MOBILE
+#ifndef MOZ_IGNORE_PAINT_WILL_RESAMPLE
   // This is handled by PadDrawTargetOutFromRegion in TiledContentClient for mobile
   if (MayResample()) {
     // If we're resampling then bilinear filtering can read up to 1 pixel
     // outside of our texture coords. Make the visible region a single rect,
     // and pad it out by 1 pixel (restricted to tile boundaries) so that
     // we always have valid content or transparent pixels to sample from.
     nsIntRect bounds = neededRegion.GetBounds();
     nsIntRect wholeTiles = bounds;

--- a/gfx/layers/composite/ContentHost.cpp
+++ b/gfx/layers/composite/ContentHost.cpp
@@ -60,25 +60,29 @@ ContentHostBase::Composite(EffectChain& 
   if (!effect) {
     return;
   }
 
   aEffectChain.mPrimaryEffect = effect;
 
   nsIntRegion tmpRegion;
   const nsIntRegion* renderRegion;
+#ifndef MOZ_IGNORE_PAINT_WILL_RESAMPLE
   if (PaintWillResample()) {
     // If we're resampling, then the texture image will contain exactly the
     // entire visible region's bounds, and we should draw it all in one quad
     // to avoid unexpected aliasing.
     tmpRegion = aVisibleRegion->GetBounds();
     renderRegion = &tmpRegion;
   } else {
     renderRegion = aVisibleRegion;
   }
+#else
+  renderRegion = aVisibleRegion;
+#endif
 
   nsIntRegion region(*renderRegion);
   nsIntPoint origin = GetOriginOffset();
   // translate into TexImage space, buffer origin might not be at texture (0,0)
   region.MoveBy(-origin);
 
   // Figure out the intersecting draw region
   gfx::IntSize texSize = source->GetSize();

--- a/gfx/layers/composite/TiledContentHost.cpp
+++ b/gfx/layers/composite/TiledContentHost.cpp
@@ -405,17 +405,17 @@ TiledContentHost::Composite(EffectChain&
     }
   }
   float lowPrecisionOpacityReduction =
         (aOpacity == 1.0f && backgroundColor.a == 1.0f)
         ? gfxPrefs::LowPrecisionOpacity() : 1.0f;
 
   nsIntRegion tmpRegion;
   const nsIntRegion* renderRegion = aVisibleRegion;
-#ifndef MOZ_GFX_OPTIMIZE_MOBILE
+#ifndef MOZ_IGNORE_PAINT_WILL_RESAMPLE
   if (PaintWillResample()) {
     // If we're resampling, then the texture image will contain exactly the
     // entire visible region's bounds, and we should draw it all in one quad
     // to avoid unexpected aliasing.
     tmpRegion = aVisibleRegion->GetBounds();
     renderRegion = &tmpRegion;
   }
 #endif