cc: Stretch textures by .5 texels to prevent out of bounds sampling

This will allow us to revert texture clamping logic that reduces
the fill rate on some devices.

Instead of requiring us to clamp texture sampling, this patch
stretches textures by .5 texels past quad bounds to avoid
blending in invalid texels when GL_LINEAR filtering is used.

BUG=173480


Review URL: https://chromiumcodereview.appspot.com/12220133

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@182116 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 3 deletions

diff --git a/cc/picture_layer_tiling_set.h b/cc/picture_layer_tiling_set.h
index ef24e41..ef059ab 100644
--- a/cc/picture_layer_tiling_set.h
+++ b/cc/picture_layer_tiling_set.h
@@ -72,11 +72,11 @@ class CC_EXPORT PictureLayerTilingSet {
   // exactly fill rect with no overlap.
   class CC_EXPORT Iterator {
    public:
-    Iterator(
-      const PictureLayerTilingSet* set,
+    Iterator(const PictureLayerTilingSet* set,
       float contents_scale,
       gfx::Rect content_rect,
-      float ideal_contents_scale);
+      float ideal_contents_scale,
+      PictureLayerTiling::LayerDeviceAlignment layerDeviceAlignment);
     ~Iterator();
 
     // Visible rect (no borders), always in the space of rect,
@@ -101,6 +101,7 @@ class CC_EXPORT PictureLayerTilingSet {
     const PictureLayerTilingSet* set_;
     float contents_scale_;
     float ideal_contents_scale_;
+    PictureLayerTiling::LayerDeviceAlignment layer_device_alignment_;
     PictureLayerTiling::Iterator tiling_iter_;
     int current_tiling_;
     int ideal_tiling_;