test_runner: Move everything else into content namespace.

content/shell/renderer/test_runner/WebTestThemeEngineMac.mm

Index: content/shell/renderer/test_runner/WebTestThemeEngineMac.mm
diff --git a/content/shell/renderer/test_runner/WebTestThemeEngineMac.mm b/content/shell/renderer/test_runner/WebTestThemeEngineMac.mm
index 6a3cb70eadc667b12b343a12c66f598d4939962d..3ec055553c479b0382469bef450cd865134d8785 100644
--- a/content/shell/renderer/test_runner/WebTestThemeEngineMac.mm
+++ b/content/shell/renderer/test_runner/WebTestThemeEngineMac.mm
@@ -67,7 +67,7 @@ static NSWindow* alwaysInactiveWindow = nil;
 
 @end
 
-namespace WebTestRunner {
+namespace content {
 
 namespace {
 
@@ -83,7 +83,7 @@ ThemeTrackEnableState stateToHIEnableState(WebThemeEngine::State state)
     }
 }
 
-}
+}  // namespace
 
 void WebTestThemeEngineMac::paintScrollbarThumb(
     WebCanvas* canvas,
@@ -174,4 +174,4 @@ void WebTestThemeEngineMac::paintNSScrollerScrollbarThumb(
     [NSGraphicsContext restoreGraphicsState];
 }
 
-}
+}  // namespace content