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

content/renderer/render_widget.cc

 // Copyright (c) 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.
 
 #include "content/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 356 matching lines @@
 void RenderWidget::OnResize(const gfx::Size& new_size,
                             const gfx::Rect& resizer_rect,
                             bool is_fullscreen) {
   Resize(new_size, resizer_rect, is_fullscreen, SEND_RESIZE_ACK);
 }
 
 void RenderWidget::OnChangeResizeRect(const gfx::Rect& resizer_rect) {
   if (resizer_rect_ != resizer_rect) {
     gfx::Rect view_rect(size_);
 
-    gfx::Rect old_damage_rect = view_rect.Intersect(resizer_rect_);
+    gfx::Rect old_damage_rect = view_rect;
+    old_damage_rect.Intersect(resizer_rect_);
     if (!old_damage_rect.IsEmpty())
       paint_aggregator_.InvalidateRect(old_damage_rect);
 
-    gfx::Rect new_damage_rect = view_rect.Intersect(resizer_rect);
+    gfx::Rect new_damage_rect = view_rect;
+    new_damage_rect.Intersect(resizer_rect);
     if (!new_damage_rect.IsEmpty())
       paint_aggregator_.InvalidateRect(new_damage_rect);
 
     resizer_rect_ = resizer_rect;
 
     if (webwidget_)
       webwidget_->didChangeWindowResizerRect();
   }
 }
 
@@ skipping 537 matching lines @@
     software_stats_.numAnimationFrames++;
     software_stats_.numFramesSentToScreen++;
   }
 
   // OK, save the pending update to a local since painting may cause more
   // invalidation.  Some WebCore rendering objects only layout when painted.
   PaintAggregator::PendingUpdate update;
   paint_aggregator_.PopPendingUpdate(&update);
 
   gfx::Rect scroll_damage = update.GetScrollDamage();
-  gfx::Rect bounds = update.GetPaintBounds().Union(scroll_damage);
+  gfx::Rect bounds = update.GetPaintBounds();
+  bounds.Union(scroll_damage);
 
   // Notify derived classes that we're about to initiate a paint.
   WillInitiatePaint();
 
   // A plugin may be able to do an optimized paint. First check this, in which
   // case we can skip all of the bitmap generation and regular paint code.
   // This optimization allows PPAPI plugins that declare themselves on top of
   // the page (like a traditional windowed plugin) to be able to animate (think
   // movie playing) without repeatedly re-painting the page underneath, or
   // copying the plugin backing store (since we can send the plugin's backing
@@ skipping 18 matching lines @@
   pending_update_params_->scale_factor = device_scale_factor_;
   next_paint_flags_ = 0;
   need_update_rect_for_auto_resize_ = false;
 
   if (update.scroll_rect.IsEmpty() &&
       !is_accelerated_compositing_active_ &&
       GetBitmapForOptimizedPluginPaint(bounds, &dib, &optimized_copy_location,
                                        &optimized_copy_rect,
                                        &dib_scale_factor)) {
     // Only update the part of the plugin that actually changed.
-    optimized_copy_rect = optimized_copy_rect.Intersect(bounds);
+    optimized_copy_rect.Intersect(bounds);
     pending_update_params_->bitmap = dib->id();
     pending_update_params_->bitmap_rect = optimized_copy_location;
     pending_update_params_->copy_rects.push_back(optimized_copy_rect);
     pending_update_params_->scale_factor = dib_scale_factor;
   } else if (!is_accelerated_compositing_active_) {
     // Compute a buffer for painting and cache it.
-    gfx::Rect pixel_bounds =
-        gfx::ToEnclosingRect(bounds.Scale(device_scale_factor_));
+    gfx::RectF scaled_bounds = bounds;
+    scaled_bounds.Scale(device_scale_factor_);
+    gfx::Rect pixel_bounds = gfx::ToEnclosingRect(scaled_bounds);
     scoped_ptr<skia::PlatformCanvas> canvas(
         RenderProcess::current()->GetDrawingCanvas(&current_paint_buf_,
                                                    pixel_bounds));
     if (!canvas.get()) {
       NOTREACHED();
       return;
     }
 
     // We may get back a smaller canvas than we asked for.
     // TODO(darin): This seems like it could cause painting problems!
@@ skipping 57 matching lines @@
   if (!is_accelerated_compositing_active_)
     DidInitiatePaint();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // WebWidgetClient
 
 void RenderWidget::didInvalidateRect(const WebRect& rect) {
   // The invalidated rect might be outside the bounds of the view.
   gfx::Rect view_rect(size_);
-  gfx::Rect damaged_rect = view_rect.Intersect(rect);
+  gfx::Rect damaged_rect = view_rect;
+  damaged_rect.Intersect(rect);
   if (damaged_rect.IsEmpty())
     return;
 
   paint_aggregator_.InvalidateRect(damaged_rect);
 
   // We may not need to schedule another call to DoDeferredUpdate.
   if (invalidation_task_posted_)
     return;
   if (!paint_aggregator_.HasPendingUpdate())
     return;
@@ skipping 19 matching lines @@
 }
 
 void RenderWidget::didScrollRect(int dx, int dy, const WebRect& clip_rect) {
   // Drop scrolls on the floor when we are in compositing mode.
   // TODO(nduca): stop WebViewImpl from sending scrolls in the first place.
   if (is_accelerated_compositing_active_)
     return;
 
   // The scrolled rect might be outside the bounds of the view.
   gfx::Rect view_rect(size_);
-  gfx::Rect damaged_rect = view_rect.Intersect(clip_rect);
+  gfx::Rect damaged_rect = view_rect;
+  damaged_rect.Intersect(clip_rect);
   if (damaged_rect.IsEmpty())
     return;
 
   paint_aggregator_.ScrollRect(dx, dy, damaged_rect);
 
   // We may not need to schedule another call to DoDeferredUpdate.
   if (invalidation_task_posted_)
     return;
   if (!paint_aggregator_.HasPendingUpdate())
     return;
@@ skipping 775 matching lines @@
   pending_smooth_scroll_gestures_.insert(std::make_pair(id, callback));
 }
 
 bool RenderWidget::WillHandleMouseEvent(const WebKit::WebMouseEvent& event) {
   return false;
 }
 
 bool RenderWidget::WebWidgetHandlesCompositorScheduling() const {
   return false;
 }