cc: Full solid layers not at origin painted incorrectly

Old code used a size, we now use a rect, and I didn't update the
quad clipping to use the origin offset.

We now correctly clip the quads, and I've updated the unit test
to use a visible rect that doesn't sit on (0,0), and will fail
without this change.

Though I wasn't able to reproduce it, it may also fix:
https://code.google.com/p/chromium/issues/detail?id=427467

BUG=18132446 (internal)

Review URL: https://codereview.chromium.org/678193002

Cr-Commit-Position: refs/heads/master@{#301519}

cc/layers/picture_layer_impl_unittest.cc

@@ -1447,7 +1447,7 @@ TEST_F(PictureLayerImplTest, SolidColorLayerHasVisibleFullCoverage) {
 
   gfx::Size tile_size(1000, 1000);
   gfx::Size layer_bounds(1500, 1500);
-  gfx::Rect visible_rect(1000, 1000);
+  gfx::Rect visible_rect(250, 250, 1000, 1000);
 
   scoped_refptr<FakePicturePileImpl> pending_pile =
       FakePicturePileImpl::CreateEmptyPile(tile_size, layer_bounds);

cc/layers/solid_color_layer_impl.cc

@@ -36,16 +36,16 @@ void SolidColorLayerImpl::AppendSolidQuads(
     AppendQuadsData* append_quads_data) {
   // We create a series of smaller quads instead of just one large one so that
   // the culler can reduce the total pixels drawn.
-  int width = visible_content_rect.width();
-  int height = visible_content_rect.height();
+  int right = visible_content_rect.right();
+  int bottom = visible_content_rect.bottom();
   for (int x = visible_content_rect.x(); x < visible_content_rect.right();
        x += kSolidQuadTileSize) {
     for (int y = visible_content_rect.y(); y < visible_content_rect.bottom();
          y += kSolidQuadTileSize) {
       gfx::Rect quad_rect(x,
                           y,
-                          std::min(width - x, kSolidQuadTileSize),
-                          std::min(height - y, kSolidQuadTileSize));
+                          std::min(right - x, kSolidQuadTileSize),
+                          std::min(bottom - y, kSolidQuadTileSize));
       gfx::Rect visible_quad_rect =
           occlusion_in_content_space.GetUnoccludedContentRect(quad_rect);
       if (visible_quad_rect.IsEmpty())