Remove redundant DevToolsManager methods and clean up its clients.

chrome/browser/devtools/devtools_sanity_browsertest.cc

Index: chrome/browser/devtools/devtools_sanity_browsertest.cc
diff --git a/chrome/browser/devtools/devtools_sanity_browsertest.cc b/chrome/browser/devtools/devtools_sanity_browsertest.cc
index f21f828851d82933df99b5f7825c132a32b42373..53a831804bb2480611e9a10e9e1e6af45fe25443 100644
--- a/chrome/browser/devtools/devtools_sanity_browsertest.cc
+++ b/chrome/browser/devtools/devtools_sanity_browsertest.cc
@@ -152,13 +152,9 @@ class DevToolsSanityTest : public InProcessBrowserTest {
 
   void CloseDevToolsWindow() {
     DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
-    // UnregisterDevToolsClientHostFor may destroy window_ so store the browser
-    // first.
+    // CloseAllClientHosts may destroy window_ so store the browser first.
     Browser* browser = window_->browser();
-    scoped_refptr<DevToolsAgentHost> agent(
-        DevToolsAgentHost::GetOrCreateFor(inspected_rvh_));
-    devtools_manager->UnregisterDevToolsClientHostFor(agent);
-
+    devtools_manager->CloseAllClientHosts();
     // Wait only when DevToolsWindow has a browser. For docked DevTools, this
     // is NULL and we skip the wait.
     if (browser)