Make gfx::Rect class operations consistently mutate the class they are called on.

Currently some methods mutate the class, and some return a new value, requiring
API users to know what kind of method they are calling each time, and making
inconsistent code. For example:

gfx::Rect rect;
rect.Inset(1, 1, 1, 1);
rect = rect.Intersect(other_rect);
rect.Offset(1, 1);

Instead of:

gfx::Rect rect;
rect.Inset(1, 1, 1, 1);
rect.Intersect(other_rect);
rect.Offset(1, 1);

We could go either way - making the class immutable or all methods return a new
instance - but I believe it is better to instead make all methods mutate the
class. This allows for shorter lines of code by avoiding having to repeat the
object's name twice in order to change it.

This patch changes gfx::Rect classes and all the callsites that uses these
methods. It should make no change in behaviour, so no new tests added.

R=sky
BUG=147395

Review URL: https://codereview.chromium.org/11110004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@163579 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 11 insertions, 4 deletions

diff --git a/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc b/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc
index 85c27d9..923b88d 100644
--- a/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc
+++ b/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc
@@ -376,7 +376,8 @@ int32_t PPB_Graphics2D_Impl::Flush(scoped_refptr<TrackedCallback> callback,
 
       // Set |no_update_visible| to false if the change overlaps the visible
       // area.
-      gfx::Rect visible_changed_rect = clip.Intersect(op_rect);
+      gfx::Rect visible_changed_rect = clip;
+      visible_changed_rect.Intersect(op_rect);
       if (!visible_changed_rect.IsEmpty())
         no_update_visible = false;
 
@@ -560,7 +561,8 @@ void PPB_Graphics2D_Impl::Paint(WebKit::WebCanvas* canvas,
 
   CGContextDrawImage(canvas, bitmap_rect, image);
 #else
-  gfx::Rect invalidate_rect = plugin_rect.Intersect(paint_rect);
+  gfx::Rect invalidate_rect = plugin_rect;
+  invalidate_rect.Intersect(paint_rect);
   SkRect sk_invalidate_rect = gfx::RectToSkRect(invalidate_rect);
   SkAutoCanvasRestore auto_restore(canvas, true);
   canvas->clipRect(sk_invalidate_rect);
@@ -647,12 +649,17 @@ bool PPB_Graphics2D_Impl::ConvertToLogicalPixels(float scale,
   // Take the enclosing rectangle after scaling so a rectangle scaled down then
   // scaled back up by the inverse scale would fully contain the entire area
   // affected by the original rectangle.
-  *op_rect = gfx::ToEnclosingRect(op_rect->Scale(scale));
+  gfx::RectF scaled_rect = *op_rect;
+  scaled_rect.Scale(scale);
+  *op_rect = gfx::ToEnclosingRect(scaled_rect);
   if (delta) {
     gfx::Point original_delta = *delta;
     float inverse_scale = 1.0f / scale;
     *delta = gfx::ToFlooredPoint(delta->Scale(scale));
-    if (original_rect != gfx::ToEnclosingRect(op_rect->Scale(inverse_scale)) ||
+
+    gfx::RectF inverse_scaled_rect = *op_rect;
+    inverse_scaled_rect.Scale(inverse_scale);
+    if (original_rect != gfx::ToEnclosingRect(inverse_scaled_rect) ||
         original_delta != gfx::ToFlooredPoint(delta->Scale(inverse_scale))) {
       return false;
     }