Plugin Power Saver: Implement pixel tests for plugin placeholders.

base/test/test_switches.cc

Index: base/test/test_switches.cc
diff --git a/base/test/test_switches.cc b/base/test/test_switches.cc
index 40f20d7b7dbebdfa66fa9acc9aee4fba1578ab23..1e3dc7ea161a7f03dfab57e64c58178c70f6b82b 100644
--- a/base/test/test_switches.cc
+++ b/base/test/test_switches.cc
@@ -66,3 +66,8 @@ const char switches::kTestLauncherTimeout[] = "test-launcher-timeout";
 const char switches::kTestTinyTimeout[] = "test-tiny-timeout";
 const char switches::kUiTestActionTimeout[] = "ui-test-action-timeout";
 const char switches::kUiTestActionMaxTimeout[] = "ui-test-action-max-timeout";
+
+#if defined(ENABLE_PLUGINS)
+// Makes browser pixel tests overwrite the reference if it does not match.
+const char switches::kRebaselinePixelTests[] = "rebaseline-pixel-tests";
+#endif