Add missing ConstrainedDialog code and re-enable disabled PrintPreviewHandlerTest tests on CrOS.

chrome/browser/ui/webui/print_preview_handler_unittest.cc

Index: chrome/browser/ui/webui/print_preview_handler_unittest.cc
===================================================================
--- chrome/browser/ui/webui/print_preview_handler_unittest.cc	(revision 110267)
+++ chrome/browser/ui/webui/print_preview_handler_unittest.cc	(working copy)
@@ -149,8 +149,7 @@
 
 // Test crashs on TouchUI due to initiator tab's native view having no parent.
 // http://crbug.com/104284
-// Test crashes on CrOS as well. http://crbug.com/104403
-#if defined(TOUCH_UI) || defined(OS_CHROMEOS)
+#if defined(TOUCH_UI)
 #define MAYBE_StickyMarginsCustom DISABLED_StickyMarginsCustom
 #else
 #define MAYBE_StickyMarginsCustom StickyMarginsCustom
@@ -174,8 +173,8 @@
   CheckCustomMargins(kMarginTop, kMarginRight, kMarginBottom, kMarginLeft);
 }
 
-// http://crbug.com/104284, http://crbug.com/104403
-#if defined(TOUCH_UI) || defined(OS_CHROMEOS)
+// http://crbug.com/104284
+#if defined(TOUCH_UI)
 #define MAYBE_StickyMarginsDefault DISABLED_StickyMarginsDefault
 #else
 #define MAYBE_StickyMarginsDefault StickyMarginsDefault
@@ -193,8 +192,8 @@
   ASSERT_FALSE(PrintPreviewHandler::last_used_page_size_margins_);
 }
 
-// http://crbug.com/104284, http://crbug.com/104403
-#if defined(TOUCH_UI) || defined(OS_CHROMEOS)
+// http://crbug.com/104284
+#if defined(TOUCH_UI)
 #define MAYBE_StickyMarginsCustomThenDefault \
     DISABLED_StickyMarginsCustomThenDefault
 #else
@@ -227,8 +226,8 @@
   CheckCustomMargins(kMarginTop, kMarginRight, kMarginBottom, kMarginLeft);
 }
 
-// http://crbug.com/104284, http://crbug.com/104403
-#if defined(TOUCH_UI) || defined(OS_CHROMEOS)
+// http://crbug.com/104284
+#if defined(TOUCH_UI)
 #define MAYBE_GetLastUsedMarginSettingsCustom \
     DISABLED_GetLastUsedMarginSettingsCustom
 #else
@@ -264,8 +263,8 @@
   EXPECT_EQ(kMarginLeft, margin_value);
 }
 
-// http://crbug.com/104284, http://crbug.com/104403
-#if defined(TOUCH_UI) || defined(OS_CHROMEOS)
+// http://crbug.com/104284
+#if defined(TOUCH_UI)
 #define MAYBE_GetLastUsedMarginSettingsDefault \
     DISABLED_GetLastUsedMarginSettingsDefault
 #else