Fixing tile grid size used by cc:Picture to make it respect current tile configuration

cc/picture_pile_base.cc

Index: cc/picture_pile_base.cc
diff --git a/cc/picture_pile_base.cc b/cc/picture_pile_base.cc
index 94983847afcc63ff943c57bb82b547c3a160243e..ac0658267a9ff952c42bc21c2961166c76ea277e 100644
--- a/cc/picture_pile_base.cc
+++ b/cc/picture_pile_base.cc
@@ -5,11 +5,15 @@
 #include "cc/picture_pile_base.h"
 
 #include "base/logging.h"
+#include "cc/layer_tree_host.h"
+#include "cc/layer_tree_host_impl.h"
 
 namespace {
 // Dimensions of the tiles in this picture pile as well as the dimensions of
 // the base picture in each tile.
 const int kBasePictureSize = 3000;
+const int kDefaultTileGridInterval = 254;

[enne (OOO), 2013/02/25 23:59:15]

This should never get used, right? If possible, I'd prefer to not have this
constant, since it might make somebody think that this value is real and gets
used.

+const int kDefaultTileGridBorderPixels = 1;
 }
 
 namespace cc {
@@ -17,6 +21,12 @@ namespace cc {
 PicturePileBase::PicturePileBase()
     : min_contents_scale_(0) {
   tiling_.SetMaxTextureSize(gfx::Size(kBasePictureSize, kBasePictureSize));
+  tile_grid_info_.fTileInterval.set(kDefaultTileGridInterval,
+      kDefaultTileGridInterval);
+  tile_grid_info_.fMargin.set(kDefaultTileGridBorderPixels,
+      kDefaultTileGridBorderPixels);
+  tile_grid_info_.fOffset.set(-kDefaultTileGridBorderPixels,
+      -kDefaultTileGridBorderPixels);
 }
 
 PicturePileBase::~PicturePileBase() {
@@ -67,6 +77,32 @@ void PicturePileBase::SetMinContentsScale(float min_contents_scale) {
   min_contents_scale_ = min_contents_scale;
 }
 
+void PicturePileBase::ApplyLayerTreeSettings(LayerTreeHost* host) {
+  ApplyLayerTreeSettings(host->settings(), host->deviceScaleFactor());
+}
+
+void PicturePileBase::ApplyLayerTreeSettings(LayerTreeHostImpl* host_impl) {
+  ApplyLayerTreeSettings(host_impl->settings(),
+      host_impl->deviceScaleFactor());
+}
+
+void PicturePileBase::ApplyLayerTreeSettings(
+  const LayerTreeSettings& settings, float deviceScaleFactor) {
+  SetMinContentsScale(settings.minimumContentsScale);
+  tile_grid_info_.fTileInterval.set(
+      settings.defaultTileSize.width() - 2 * kDefaultTileGridBorderPixels,
+      settings.defaultTileSize.height() - 2 * kDefaultTileGridBorderPixels);
+  DCHECK_GT(tile_grid_info_.fTileInterval.width(), 0);
+  DCHECK_GT(tile_grid_info_.fTileInterval.height(), 0);
+  tile_grid_info_.fMargin.set(kDefaultTileGridBorderPixels,
+      kDefaultTileGridBorderPixels);
+  // Offset the tile grid coordinate space to take into account the fact
+  // that the top-most and left-most tiles do not have top and left borders
+  // respectively.
+  tile_grid_info_.fOffset.set(-kDefaultTileGridBorderPixels,
+      -kDefaultTileGridBorderPixels);
+}
+
 void PicturePileBase::SetBufferPixels(int new_buffer_pixels) {
   if (new_buffer_pixels == buffer_pixels())
     return;
@@ -84,6 +120,7 @@ void PicturePileBase::PushPropertiesTo(PicturePileBase* other) {
   other->tiling_ = tiling_;
   other->recorded_region_ = recorded_region_;
   other->min_contents_scale_ = min_contents_scale_;
+  other->tile_grid_info_ = tile_grid_info_;
 }
 
 void PicturePileBase::UpdateRecordedRegion() {