Fix memory issues in compositor_unittests

These LayerDelegates are trying to paint rectangles at offsets, but end
up always painting their rectangles at the layer origin.  This causes
any scheduled paint not at the origin to not fill the entire
invalidation, leading to uninitialized pixels being drawn.

The fix is rather than drawing a rect at the origin, just fill the
entire clip with the right color.  The clip is in the right place, so
this will do what the test intends.

Also fill the canvas in the DrawTreeLayerDelegate, which was always
leaving it uninitialized.

R=piman@chromium.org,danakj@chromium.org
BUG=421107

Review URL: https://codereview.chromium.org/637933004

Cr-Commit-Position: refs/heads/master@{#298817}

1 files changed, 2 insertions, 1 deletions

diff --git a/ui/compositor/layer_unittest.cc b/ui/compositor/layer_unittest.cc
index c74d5c8..ac534f8 100644
--- a/ui/compositor/layer_unittest.cc
+++ b/ui/compositor/layer_unittest.cc
@@ -237,7 +237,7 @@ class TestLayerDelegate : public LayerDelegate {
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
     SkISize size = canvas->sk_canvas()->getBaseLayerSize();
     paint_size_ = gfx::Size(size.width(), size.height());
-    canvas->FillRect(gfx::Rect(paint_size_), colors_[color_index_]);
+    canvas->DrawColor(colors_[color_index_]);
     color_index_ = (color_index_ + 1) % static_cast<int>(colors_.size());
     const SkMatrix& matrix = canvas->sk_canvas()->getTotalMatrix();
     scale_x_ = matrix.getScaleX();
@@ -289,6 +289,7 @@ class DrawTreeLayerDelegate : public LayerDelegate {
   // Overridden from LayerDelegate:
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
     painted_ = true;
+    canvas->DrawColor(SK_ColorTRANSPARENT);
   }
   virtual void OnDelegatedFrameDamage(
       const gfx::Rect& damage_rect_in_dip) OVERRIDE {}