Disable flaky browser tests on Mac.

chrome/browser/plugins/plugin_power_saver_browsertest.cc

 // Copyright 2015 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 <stdint.h>
 #include <string>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/stl_util.h"
@@ skipping 393 matching lines @@
   VerifyPluginMarkedEssential(GetActiveWebContents(), "small_same_origin");
   VerifyPluginMarkedEssential(GetActiveWebContents(),
                               "small_same_origin_poster");
   VerifyPluginMarkedEssential(GetActiveWebContents(), "tiny_cross_origin_1");
   VerifyPluginMarkedEssential(GetActiveWebContents(), "tiny_cross_origin_2");
   VerifyPluginMarkedEssential(GetActiveWebContents(), "large_cross_origin");
   VerifyPluginMarkedEssential(GetActiveWebContents(),
                               "medium_16_9_cross_origin");
 }
 
-IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, SmallCrossOrigin) {
+// Flaky on WebKit Mac dbg bots: crbug.com/599484.
+#if defined(OS_MACOSX)
+#define MAYBE_SmallCrossOrigin DISABLED_SmallCrossOrigin
+#else
+#define MAYBE_SmallCrossOrigin SmallCrossOrigin
+#endif
+IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, MAYBE_SmallCrossOrigin) {
   LoadHTML(
       "<object id='plugin' data='http://otherorigin.com/fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='100'>"
       "</object>"
       "<br>"
       "<object id='plugin_poster' data='http://otherorigin.com/fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='100' "
       "    poster='click_me.png'>"
       "</object>");
 
@@ skipping 20 matching lines @@
 
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_16");
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_32");
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_16_64");
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin_64_16");
 
   EXPECT_TRUE(
       VerifySnapshot(FILE_PATH_LITERAL("smaller_than_play_icon_expected.png")));
 }
 
-IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, PosterTests) {
+// Flaky on WebKit Mac dbg bots: crbug.com/599484.
+#if defined(OS_MACOSX)
+#define MAYBE_PosterTests DISABLED_PosterTests
+#else
+#define MAYBE_PosterTests PosterTests
+#endif
+IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, MAYBE_PosterTests) {
   // This test simultaneously verifies the varied supported poster syntaxes,
   // as well as verifies that the poster is rendered correctly with various
   // mismatched aspect ratios and sizes, following the same rules as VIDEO.
   LoadHTML(
       "<object id='plugin_src' type='application/x-ppapi-tests' "
       "    width='100' height='100' poster='click_me.png'></object>"
       "<object id='plugin_srcset' type='application/x-ppapi-tests' "
       "    width='100' height='100' "
       "    poster='click_me.png 1x, click_me.png 2x'></object>"
       "<br>"
@@ skipping 167 matching lines @@
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, ZoomIndependent) {
   ui_zoom::ZoomController::FromWebContents(GetActiveWebContents())
       ->SetZoomLevel(4.0);
   LoadHTML(
       "<object id='plugin' data='http://otherorigin.com/fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='200'>"
       "</object>");
   VerifyPluginIsThrottled(GetActiveWebContents(), "plugin");
 }