Move SnapToPhysicalPixelBoundary call to RWHVA::InternalSetBounds

RWHVAura::SetBounds isn't actually called in most situations, so the snapping
wasn't occuring when it should. ::SetSize is actually called when the bounds
of the RWHVA changes and both call ::InternalSetBounds(), so this calls the
snapping logic there.

BUG=370074

Review URL: https://codereview.chromium.org/317633006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275994 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 13 insertions, 5 deletions

diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 6bec9f2..8f2cd85 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -623,7 +623,6 @@ void RenderWidgetHostViewAura::SetBounds(const gfx::Rect& rect) {
     }
   }
 
-  SnapToPhysicalPixelBoundary();
   InternalSetBounds(gfx::Rect(relative_origin, rect.size()));
 }
 
@@ -987,15 +986,14 @@ void RenderWidgetHostViewAura::SnapToPhysicalPixelBoundary() {
 
   gfx::Vector2dF fudge = view_offset_snapped - view_offset;
   fudge.Scale(1.0 / current_device_scale_factor_);
-  gfx::Transform fudge_transform;
-  fudge_transform.Translate(fudge.x(), fudge.y());
-  GetLayer()->cc_layer()->SetTransform(fudge_transform);
+  GetLayer()->SetSubpixelPositionOffset(fudge);
 }
 
 void RenderWidgetHostViewAura::InternalSetBounds(const gfx::Rect& rect) {
   if (HasDisplayPropertyChanged(window_))
     host_->InvalidateScreenInfo();
 
+  SnapToPhysicalPixelBoundary();
   // Don't recursively call SetBounds if this bounds update is the result of
   // a Window::SetBoundsInternal call.
   if (!in_bounds_changed_)
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index 17ab899..150e1ef 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -243,6 +243,11 @@ void Layer::SetBounds(const gfx::Rect& bounds) {
   GetAnimator()->SetBounds(bounds);
 }
 
+void Layer::SetSubpixelPositionOffset(const gfx::Vector2dF offset) {
+  subpixel_position_offset_ = offset;
+  RecomputePosition();
+}
+
 gfx::Rect Layer::GetTargetBounds() const {
   if (animator_.get() && animator_->IsAnimatingProperty(
       LayerAnimationElement::BOUNDS)) {
@@ -959,7 +964,7 @@ void Layer::RecomputeDrawsContentAndUVRect() {
 }
 
 void Layer::RecomputePosition() {
-  cc_layer_->SetPosition(gfx::PointF(bounds_.x(), bounds_.y()));
+  cc_layer_->SetPosition(bounds_.origin() + subpixel_position_offset_);
 }
 
 void Layer::AddAnimatorsInTreeToCollection(
diff --git a/ui/compositor/layer.h b/ui/compositor/layer.h
index 069f167..03041ed 100644
--- a/ui/compositor/layer.h
+++ b/ui/compositor/layer.h
@@ -139,6 +139,10 @@ class COMPOSITOR_EXPORT Layer
   void SetBounds(const gfx::Rect& bounds);
   const gfx::Rect& bounds() const { return bounds_; }
 
+  // The offset from our parent (stored in bounds.origin()) is an integer but we
+  // may need to be at a fractional pixel offset to align properly on screen.
+  void SetSubpixelPositionOffset(const gfx::Vector2dF offset);
+
   // Return the target bounds if animator is running, or the current bounds
   // otherwise.
   gfx::Rect GetTargetBounds() const;
@@ -410,6 +414,7 @@ class COMPOSITOR_EXPORT Layer
   std::vector<Layer*> children_;
 
   gfx::Rect bounds_;
+  gfx::Vector2dF subpixel_position_offset_;
 
   // Visibility of this layer. See SetVisible/IsDrawn for more details.
   bool visible_;