Move a bunch of content\common code into the content namespace.

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"
 
+namespace content {
+
 TEST(PaintAggregator, InitialState) {
   PaintAggregator greg;
   EXPECT_FALSE(greg.HasPendingUpdate());
 }
 
 TEST(PaintAggregator, SingleInvalidation) {
   PaintAggregator greg;
 
   gfx::Rect rect(2, 4, 10, 16);
   greg.InvalidateRect(rect);
@@ skipping 410 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());
 }
+
+}  // namespace content