Simplify how Content*Client interfaces are created. Instead of depending on the embedder to know wh…

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
===================================================================
--- content/app/content_main_runner.cc	(revision 140381)
+++ content/app/content_main_runner.cc	(working copy)
@@ -11,6 +11,7 @@
 #include "base/debug/trace_event.h"
 #include "base/file_path.h"
 #include "base/i18n/icu_util.h"
+#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/stats_table.h"
@@ -23,12 +24,16 @@
 #include "content/common/url_schemes.h"
 #include "content/public/app/content_main_delegate.h"
 #include "content/public/app/startup_helper_win.h"
+#include "content/public/browser/content_browser_client.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/main_function_params.h"
 #include "content/public/common/sandbox_init.h"
+#include "content/public/plugin/content_plugin_client.h"
+#include "content/public/renderer/content_renderer_client.h"
+#include "content/public/utility/content_utility_client.h"
 #include "crypto/nss_util.h"
 #include "ipc/ipc_switches.h"
 #include "media/base/media.h"
@@ -81,13 +86,22 @@
 extern int UtilityMain(const content::MainFunctionParams&);
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
 namespace content {
-extern int ZygoteMain(const content::MainFunctionParams&,
-                      content::ZygoteForkDelegate* forkdelegate);
+extern int ZygoteMain(const MainFunctionParams&,
+                      ZygoteForkDelegate* forkdelegate);
 }  // namespace content
 #endif
 
-namespace {
+namespace content {
 
+base::LazyInstance<ContentBrowserClient>
+    g_empty_content_browser_client = LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<ContentPluginClient>
+    g_empty_content_plugin_client = LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<ContentRendererClient>
+    g_empty_content_renderer_client = LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<ContentUtilityClient>
+    g_empty_content_utility_client = LAZY_INSTANCE_INITIALIZER;
+
 #if defined(OS_WIN)
 
 static CAppModule _Module;
@@ -206,20 +220,50 @@
     // NOTIMPLEMENTED: we probably need to shut this down correctly to avoid
     // leaking shared memory regions on posix platforms.
     std::string statsfile =
-      base::StringPrintf(
-          "%s-%u", content::kStatsFilename,
+      base::StringPrintf("%s-%u", kStatsFilename,
           static_cast<unsigned int>(GetBrowserPid(command_line)));
     base::StatsTable* stats_table = new base::StatsTable(statsfile,
-        content::kStatsMaxThreads, content::kStatsMaxCounters);
+        kStatsMaxThreads, kStatsMaxCounters);
     base::StatsTable::set_current(stats_table);
   }
 }
 
+class ContentClientInitializer {
+ public:
+  static void Set(const std::string& process_type,
+                  ContentMainDelegate* delegate) {
+    ContentClient* content_client = GetContentClient();
+    if (process_type.empty()) {
+      if (delegate)
+        content_client->browser_ = delegate->CreateContentBrowserClient();
+      if (!content_client->browser_)
+        content_client->browser_ = &g_empty_content_browser_client.Get();
+    }
+
+    if (process_type == switches::kPluginProcess) {
+      if (delegate)
+        content_client->plugin_ = delegate->CreateContentPluginClient();
+      if (!content_client->plugin_)
+        content_client->plugin_ = &g_empty_content_plugin_client.Get();
+    } else if (process_type == switches::kRendererProcess) {
+      if (delegate)
+        content_client->renderer_ = delegate->CreateContentRendererClient();
+      if (!content_client->renderer_)
+        content_client->renderer_ = &g_empty_content_renderer_client.Get();
+    } else if (process_type == switches::kUtilityProcess) {
+      if (delegate)
+        content_client->utility_ = delegate->CreateContentUtilityClient();
+      if (!content_client->utility_)
+        content_client->utility_ = &g_empty_content_utility_client.Get();
+    }
+  }
+};
+
 // We dispatch to a process-type-specific FooMain() based on a command-line
 // flag.  This struct is used to build a table of (flag, main function) pairs.
 struct MainFunction {
   const char* name;
-  int (*function)(const content::MainFunctionParams&);
+  int (*function)(const MainFunctionParams&);
 };
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
@@ -227,8 +271,8 @@
 // subprocesses that are launched via the zygote.  This function
 // fills in some process-launching bits around ZygoteMain().
 // Returns the exit code of the subprocess.
-int RunZygote(const content::MainFunctionParams& main_function_params,
-              content::ContentMainDelegate* delegate) {
+int RunZygote(const MainFunctionParams& main_function_params,
+              ContentMainDelegate* delegate) {
   static const MainFunction kMainFunctions[] = {
     { switches::kRendererProcess,    RendererMain },
     { switches::kWorkerProcess,      WorkerMain },
@@ -236,19 +280,19 @@
     { switches::kUtilityProcess,     UtilityMain },
   };
 
-  scoped_ptr<content::ZygoteForkDelegate> zygote_fork_delegate;
+  scoped_ptr<ZygoteForkDelegate> zygote_fork_delegate;
   if (delegate) {
     zygote_fork_delegate.reset(delegate->ZygoteStarting());
     // Each Renderer we spawn will re-attempt initialization of the media
     // libraries, at which point failure will be detected and handled, so
     // we do not need to cope with initialization failures here.
     FilePath media_path;
-    if (PathService::Get(content::DIR_MEDIA_LIBS, &media_path))
+    if (PathService::Get(DIR_MEDIA_LIBS, &media_path))
       media::InitializeMediaLibrary(media_path);
   }
 
   // This function call can return multiple times, once per fork().
-  if (!content::ZygoteMain(main_function_params, zygote_fork_delegate.get()))
+  if (!ZygoteMain(main_function_params, zygote_fork_delegate.get()))
     return 1;
 
   if (delegate) delegate->ZygoteForked();
@@ -256,6 +300,9 @@
   // Zygote::HandleForkRequest may have reallocated the command
   // line so update it here with the new version.
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  std::string process_type =
+      command_line.GetSwitchValueASCII(switches::kProcessType);
+  ContentClientInitializer::Set(process_type, delegate);
 
   // If a custom user agent was passed on the command line, we need
   // to (re)set it now, rather than using the default one the zygote
@@ -270,12 +317,8 @@
   // within the new processes as well.
   InitializeStatsTable(command_line);
 
-  content::MainFunctionParams main_params(command_line);
+  MainFunctionParams main_params(command_line);
 
-  // Get the new process type from the new command line.
-  std::string process_type =
-      command_line.GetSwitchValueASCII(switches::kProcessType);
-
   for (size_t i = 0; i < arraysize(kMainFunctions); ++i) {
     if (process_type == kMainFunctions[i].name)
       return kMainFunctions[i].function(main_params);
@@ -294,8 +337,8 @@
 // Returns the exit code for this process.
 int RunNamedProcessTypeMain(
     const std::string& process_type,
-    const content::MainFunctionParams& main_function_params,
-    content::ContentMainDelegate* delegate) {
+    const MainFunctionParams& main_function_params,
+    ContentMainDelegate* delegate) {
   static const MainFunction kMainFunctions[] = {
     { "",                            BrowserMain },
     { switches::kRendererProcess,    RendererMain },
@@ -334,7 +377,7 @@
   return 1;
 }
 
-class ContentMainRunnerImpl : public content::ContentMainRunner {
+class ContentMainRunnerImpl : public ContentMainRunner {
  public:
   ContentMainRunnerImpl()
       : is_initialized_(false),
@@ -361,12 +404,12 @@
 #if defined(OS_WIN)
   virtual int Initialize(HINSTANCE instance,
                          sandbox::SandboxInterfaceInfo* sandbox_info,
-                         content::ContentMainDelegate* delegate) OVERRIDE {
+                         ContentMainDelegate* delegate) OVERRIDE {
     // argc/argv are ignored on Windows; see command_line.h for details.
     int argc = 0;
     char** argv = NULL;
 
-    content::RegisterInvalidParamHandler();
+    RegisterInvalidParamHandler();
     _Module.Init(NULL, static_cast<HINSTANCE>(instance));
 
     if (sandbox_info)
@@ -377,7 +420,7 @@
 #else  // !OS_WIN
   virtual int Initialize(int argc,
                          const char** argv,
-                         content::ContentMainDelegate* delegate) OVERRIDE {
+                         ContentMainDelegate* delegate) OVERRIDE {
 
     // NOTE(willchan): One might ask why this call is done here rather than in
     // process_util_linux.cc with the definition of
@@ -448,15 +491,17 @@
     int exit_code;
     if (delegate && delegate->BasicStartupComplete(&exit_code))
       return exit_code;
-    DCHECK(!delegate || content::GetContentClient()) <<
-        "BasicStartupComplete didn't set the content client";
 
     completed_basic_startup_ = true;
 
     const CommandLine& command_line = *CommandLine::ForCurrentProcess();
     std::string process_type =
-          command_line.GetSwitchValueASCII(switches::kProcessType);
+        command_line.GetSwitchValueASCII(switches::kProcessType);
 
+    if (!GetContentClient())
+      SetContentClient(&empty_content_client_);
+    ContentClientInitializer::Set(process_type, delegate_);
+
     // Enable startup tracing asap to avoid early TRACE_EVENT calls being
     // ignored.
     if (command_line.HasSwitch(switches::kTraceStartup)) {
@@ -487,7 +532,7 @@
 #if defined(ENABLE_HIDPI)
     ui::EnableHighDPISupport();
 #endif
-    content::SetupCRT(command_line);
+    SetupCRT(command_line);
 #endif
 
 #if defined(OS_POSIX)
@@ -513,8 +558,8 @@
 #endif
 
     ui::RegisterPathProvider();
-    content::RegisterPathProvider();
-    content::RegisterContentSchemes(true);
+    RegisterPathProvider();
+    RegisterContentSchemes(true);
 
     CHECK(icu_util::Initialize());
 
@@ -535,7 +580,7 @@
       CommonSubprocessInit(process_type);
 
 #if defined(OS_WIN)
-    CHECK(content::InitializeSandbox(sandbox_info));
+    CHECK(InitializeSandbox(sandbox_info));
 #elif defined(OS_MACOSX)
     if (process_type == switches::kRendererProcess ||
         process_type == switches::kPpapiPluginProcess ||
@@ -543,7 +588,7 @@
       // On OS X the renderer sandbox needs to be initialized later in the
       // startup sequence in RendererMainPlatformDelegate::EnableSandbox().
     } else {
-      CHECK(content::InitializeSandbox());
+      CHECK(InitializeSandbox());
     }
 #endif
 
@@ -565,7 +610,7 @@
     std::string process_type =
           command_line.GetSwitchValueASCII(switches::kProcessType);
 
-    content::MainFunctionParams main_params(command_line);
+    MainFunctionParams main_params(command_line);
 #if defined(OS_WIN)
     main_params.sandbox_info = &sandbox_info_;
 #elif defined(OS_MACOSX)
@@ -605,7 +650,7 @@
     is_shutdown_ = true;
   }
 
- protected:
+ private:
   // True if the runner has been initialized.
   bool is_initialized_;
 
@@ -615,8 +660,11 @@
   // True if basic startup was completed.
   bool completed_basic_startup_;
 
+  // Used if the embedder doesn't set one.
+  ContentClient empty_content_client_;
+
   // The delegate will outlive this object.
-  content::ContentMainDelegate* delegate_;
+  ContentMainDelegate* delegate_;
 
   scoped_ptr<base::AtExitManager> exit_manager_;
 #if defined(OS_WIN)
@@ -628,10 +676,6 @@
   DISALLOW_COPY_AND_ASSIGN(ContentMainRunnerImpl);
 };
 
-}  // namespace
-
-namespace content {
-
 // static
 ContentMainRunner* ContentMainRunner::Create() {
   return new ContentMainRunnerImpl();