Launch processes asynchronously so as not to block the UI thread. For now, re...

chrome/browser/renderer_host/browser_render_process_host.h

Index: chrome/browser/renderer_host/browser_render_process_host.h
===================================================================
--- chrome/browser/renderer_host/browser_render_process_host.h	(revision 32255)
+++ chrome/browser/renderer_host/browser_render_process_host.h	(working copy)
@@ -8,6 +8,7 @@
 #include "build/build_config.h"
 
 #include <map>
+#include <queue>
 #include <string>
 
 #include "base/process.h"
@@ -17,6 +18,7 @@
 #include "base/string16.h"
 #include "base/timer.h"
 #include "chrome/common/transport_dib.h"
+#include "chrome/browser/child_process_launcher.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/common/notification_registrar.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebCache.h"
@@ -49,7 +51,8 @@
 // are correlated with IDs. This way, the Views and the corresponding ViewHosts
 // communicate through the two process objects.
 class BrowserRenderProcessHost : public RenderProcessHost,
-                                 public NotificationObserver {
+                                 public NotificationObserver,
+                                 public ChildProcessLauncher::Client {
  public:
   explicit BrowserRenderProcessHost(Profile* profile);
   ~BrowserRenderProcessHost();
@@ -68,6 +71,7 @@
   virtual void WidgetHidden();
   virtual void ViewCreated();
   virtual void AddWord(const string16& word);
+  virtual void SendVisitedLinkTable(base::SharedMemory* table_memory);
   virtual void AddVisitedLinks(const VisitedLinkCommon::Fingerprints& links);
   virtual void ResetVisitedLinks();
   virtual bool FastShutdownIfPossible();
@@ -94,6 +98,9 @@
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
+  // ChildProcessLauncher::Client implementation.
+  virtual void OnProcessLaunched();
+
  private:
   friend class VisitRelayingRenderProcessHost;
 
@@ -122,11 +129,8 @@
   void SendUserScriptsUpdate(base::SharedMemory* shared_memory);
 
   // Generates a command line to be used to spawn a renderer and appends the
-  // results to |*command_line|. |*has_cmd_prefix| will be set if the renderer
-  // command line specifies a prefix which is another program that will actually
-  // execute the renderer (like gdb).
-  void AppendRendererCommandLine(CommandLine* command_line,
-                                 bool* has_cmd_prefix) const;
+  // results to |*command_line|.
+  void AppendRendererCommandLine(CommandLine* command_line) const;
 
   // Copies applicable command line switches from the given |browser_cmd| line
   // flags to the output |renderer_cmd| line flags. Not all switches will be
@@ -134,13 +138,6 @@
   void PropogateBrowserCommandLineToRenderer(const CommandLine& browser_cmd,
                                              CommandLine* renderer_cmd) const;
 
-  // Spawns the renderer process, returning the new handle on success, or 0 on
-  // failure. The renderer command line is given in the first argument, and
-  // whether a command prefix was used when generating the command line is
-  // speficied in the second.
-  base::ProcessHandle ExecuteRenderer(CommandLine* cmd_line,
-                                      bool has_cmd_prefix);
-
   // Callers can reduce the RenderProcess' priority.
   // Returns true if the priority is backgrounded; false otherwise.
   void SetBackgrounded(bool boost);
@@ -201,15 +198,18 @@
   // Buffer visited links and send them to to renderer.
   scoped_ptr<VisitedLinkUpdater> visited_link_updater_;
 
-  // True iff the renderer is a child of a zygote process.
-  bool zygote_child_;
-
   // True iff this process is being used as an extension process. Not valid
   // when running in single-process mode.
   bool extension_process_;
 
-  base::Process process_;
+  // Usedt to launch and terminate the process without blocking the UI thread.
+  scoped_ptr<ChildProcessLauncher> child_process_;
 
+  // Messages we queue while waiting for the process handle.  We queue them here
+  // instead of in the channel so that we ensure they're sent after init related
+  // messages that are sent once the process handle is available.  This is
+  // because the queued messages may have dependencies on the init messages.
+  std::queue<IPC::Message*> queued_messages_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserRenderProcessHost);
 };