Don't call WebCacheManager::Remove(RPH_id) to clear webview's cache.

chrome/browser/apps/guest_view/web_view_browsertest.cc

Index: chrome/browser/apps/guest_view/web_view_browsertest.cc
diff --git a/chrome/browser/apps/guest_view/web_view_browsertest.cc b/chrome/browser/apps/guest_view/web_view_browsertest.cc
index 1f2526d009d601d8e73fa8d21b8e804bc993c084..65813da0ec22b3df5e81cc0e2a7471e40cd63d94 100644
--- a/chrome/browser/apps/guest_view/web_view_browsertest.cc
+++ b/chrome/browser/apps/guest_view/web_view_browsertest.cc
@@ -2268,6 +2268,14 @@ IN_PROC_BROWSER_TEST_P(WebViewTest, ClearData) {
           << message_;
 }
 
+// Regression test for https://crbug.com/615429.
+IN_PROC_BROWSER_TEST_P(WebViewTest, ClearDataTwice) {
+  ASSERT_TRUE(StartEmbeddedTestServer());  // For serving guest pages.
+  ASSERT_TRUE(RunPlatformAppTestWithArg("platform_apps/web_view/common",
+                                        "cleardata_twice"))
+      << message_;
+}
+
 #if defined(OS_WIN)
 // Test is disabled on Windows because it fails often (~9% time)
 // http://crbug.com/489088