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

content/renderer/paint_aggregator_unittest.cc

 // Copyright (c) 2009 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/paint_aggregator.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(PaintAggregator, InitialState) {
   PaintAggregator greg;
   EXPECT_FALSE(greg.HasPendingUpdate());
@@ skipping 17 matching lines @@
 
 TEST(PaintAggregator, DoubleDisjointInvalidation) {
   PaintAggregator greg;
 
   gfx::Rect r1(2, 4, 2, 40);
   gfx::Rect r2(4, 2, 40, 2);
 
   greg.InvalidateRect(r1);
   greg.InvalidateRect(r2);
 
-  gfx::Rect expected_bounds = r1.Union(r2);
+  gfx::Rect expected_bounds = r1;
+  expected_bounds.Union(r2);
 
   EXPECT_TRUE(greg.HasPendingUpdate());
   PaintAggregator::PendingUpdate update;
   greg.PopPendingUpdate(&update);
 
   EXPECT_TRUE(update.scroll_rect.IsEmpty());
   EXPECT_EQ(2U, update.paint_rects.size());
 
   EXPECT_EQ(expected_bounds, update.GetPaintBounds());
 }
 
 TEST(PaintAggregator, DisjointInvalidationsCombined) {
   PaintAggregator greg;
 
   // Make the rectangles such that they don't overlap but cover a very large
   // percentage of the area of covered by their union. This is so we're not
   // very sensitive to the combining heuristic in the paint aggregator.
   gfx::Rect r1(2, 4, 2, 1000);
   gfx::Rect r2(5, 2, 2, 1000);
 
   greg.InvalidateRect(r1);
   greg.InvalidateRect(r2);
 
-  gfx::Rect expected_bounds = r1.Union(r2);
+  gfx::Rect expected_bounds = r1;
+  expected_bounds.Union(r2);
 
   EXPECT_TRUE(greg.HasPendingUpdate());
   PaintAggregator::PendingUpdate update;
   greg.PopPendingUpdate(&update);
 
   EXPECT_TRUE(update.scroll_rect.IsEmpty());
   ASSERT_EQ(1U, update.paint_rects.size());
 
   EXPECT_EQ(expected_bounds, update.paint_rects[0]);
 }
@@ skipping 195 matching lines @@
 
 TEST(PaintAggregator, OverlappingPaintBeforeScroll) {
   PaintAggregator greg;
 
   gfx::Rect paint_rect(4, 4, 10, 2);
   greg.InvalidateRect(paint_rect);
 
   gfx::Rect scroll_rect(0, 0, 10, 10);
   greg.ScrollRect(2, 0, scroll_rect);
 
-  gfx::Rect expected_paint_rect = scroll_rect.Union(paint_rect);
+  gfx::Rect expected_paint_rect = scroll_rect;
+  expected_paint_rect.Union(paint_rect);
 
   EXPECT_TRUE(greg.HasPendingUpdate());
   PaintAggregator::PendingUpdate update;
   greg.PopPendingUpdate(&update);
 
   EXPECT_TRUE(update.scroll_rect.IsEmpty());
   EXPECT_EQ(1U, update.paint_rects.size());
 
   EXPECT_EQ(expected_paint_rect, update.paint_rects[0]);
 }
 
 TEST(PaintAggregator, OverlappingPaintAfterScroll) {
   PaintAggregator greg;
 
   gfx::Rect scroll_rect(0, 0, 10, 10);
   greg.ScrollRect(2, 0, scroll_rect);
 
   gfx::Rect paint_rect(4, 4, 10, 2);
   greg.InvalidateRect(paint_rect);
 
-  gfx::Rect expected_paint_rect = scroll_rect.Union(paint_rect);
+  gfx::Rect expected_paint_rect = scroll_rect;
+  expected_paint_rect.Union(paint_rect);
 
   EXPECT_TRUE(greg.HasPendingUpdate());
   PaintAggregator::PendingUpdate update;
   greg.PopPendingUpdate(&update);
 
   EXPECT_TRUE(update.scroll_rect.IsEmpty());
   EXPECT_EQ(1U, update.paint_rects.size());
 
   EXPECT_EQ(expected_paint_rect, update.paint_rects[0]);
 }
@@ skipping 118 matching lines @@
   EXPECT_TRUE(greg.HasPendingUpdate());
   PaintAggregator::PendingUpdate update;
   greg.PopPendingUpdate(&update);
 
   EXPECT_FALSE(update.scroll_rect.IsEmpty());
   EXPECT_TRUE(update.paint_rects.empty());
 
   EXPECT_EQ(scroll_rect, update.scroll_rect);
   EXPECT_EQ(expected_scroll_damage, update.GetScrollDamage());
 }