cc: Refactor content scale/bounds into draw properties

cc/draw_properties.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_DRAW_PROPERTIES_H_
 #define CC_DRAW_PROPERTIES_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 
 // Container for properties that layers need to compute before they can be
 // drawn.
 template<typename LayerType, typename RenderSurfaceType>
 struct CC_EXPORT DrawProperties {
     DrawProperties()
-        : opacity(0)
-        , opacity_is_animating(false)
-        , target_space_transform_is_animating(false)
-        , screen_space_transform_is_animating(false)
-        , is_clipped(false)
-        , render_target(0)
+        : opacity(0),
+          opacity_is_animating(false),
+          target_space_transform_is_animating(false),
+          screen_space_transform_is_animating(false),
+          is_clipped(false),
+          render_target(0),
+          ideal_contents_scale(1),
+          contents_scale_x(1),
+          contents_scale_y(1)
     {
     }
 
     // Transforms objects from content space to target surface space, where
     // this layer would be drawn.
     gfx::Transform target_space_transform;
 
     // Transforms objects from content space to screen space (viewport space).
     gfx::Transform screen_space_transform;
 
@@ skipping 25 matching lines @@
     gfx::Rect visible_content_rect;
 
     // In target surface space, the rect that encloses the clipped, drawable
     // content of the layer.
     gfx::Rect drawable_content_rect;
 
     // In target surface space, the original rect that clipped this
     // layer. This value is used to avoid unnecessarily changing GL scissor
     // state.
     gfx::Rect clip_rect;
+
+    float ideal_contents_scale;

[shawnsingh, 2012/12/11 21:54:05]

Conceptually, it seems like ideal_contents_scale is merely a temporary value
that is passed to setIdealContentsScale() for the purposes of computing
contents_scale_x and contents_scale_y.

If it's really needed for contents_scaling_layer and possibly image_layer,
perhaps we should make it a private variable unique to those classes, instead of
keeping it here.

[enne (OOO), 2012/12/11 23:23:44]

Ok, sure.  I can store it elsewhere.  I just thought it might be useful to store
here in one place since it was something that all layers calculated.

+    float contents_scale_x;
+    float contents_scale_y;
+    gfx::Size content_bounds;
 };
 
 }  // namespace cc
 
 #endif  // CC_DRAW_PROPERTIES_H_