Allow overlapping sync and async startup requests

On Android we can get a second request to start the browser while
the an asynchronous request is in progress. Since the second
request may be synchronous, we may have switch to completing
initialization synchronously. This patch handles this by tracking
which initialization tasks have been run, and running the remaining
initialization tasks.

BUG=260574

Review URL: https://chromiumcodereview.appspot.com/22691002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@219795 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 39 insertions, 22 deletions

diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 8bf6503..87bec3d 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -527,36 +527,53 @@ int BrowserMainLoop::PreCreateThreads() {
 }
 
 void BrowserMainLoop::CreateStartupTasks() {
-  TRACE_EVENT0("startup", "BrowserMainLoop::CreateStartupTasks")
+  TRACE_EVENT0("startup", "BrowserMainLoop::CreateStartupTasks");
 
+  // First time through, we really want to create all the tasks
+  if (!startup_task_runner_.get()) {
 #if defined(OS_ANDROID)
-  scoped_refptr<StartupTaskRunner> task_runner =
-      new StartupTaskRunner(BrowserMayStartAsynchronously(),
-                            base::Bind(&BrowserStartupComplete),
-                            base::MessageLoop::current()->message_loop_proxy());
+    startup_task_runner_ = make_scoped_ptr(new StartupTaskRunner(
+        base::Bind(&BrowserStartupComplete),
+        base::MessageLoop::current()->message_loop_proxy()));
 #else
-  scoped_refptr<StartupTaskRunner> task_runner =
-      new StartupTaskRunner(false,
-                            base::Callback<void(int)>(),
-                            base::MessageLoop::current()->message_loop_proxy());
+    startup_task_runner_ = make_scoped_ptr(new StartupTaskRunner(
+        base::Callback<void(int)>(),
+        base::MessageLoop::current()->message_loop_proxy()));
 #endif
-  StartupTask pre_create_threads =
-      base::Bind(&BrowserMainLoop::PreCreateThreads, base::Unretained(this));
-  task_runner->AddTask(pre_create_threads);
+    StartupTask pre_create_threads =
+        base::Bind(&BrowserMainLoop::PreCreateThreads, base::Unretained(this));
+    startup_task_runner_->AddTask(pre_create_threads);
 
-  StartupTask create_threads =
-      base::Bind(&BrowserMainLoop::CreateThreads, base::Unretained(this));
-  task_runner->AddTask(create_threads);
+    StartupTask create_threads =
+        base::Bind(&BrowserMainLoop::CreateThreads, base::Unretained(this));
+    startup_task_runner_->AddTask(create_threads);
 
-  StartupTask browser_thread_started = base::Bind(
-      &BrowserMainLoop::BrowserThreadsStarted, base::Unretained(this));
-  task_runner->AddTask(browser_thread_started);
+    StartupTask browser_thread_started = base::Bind(
+        &BrowserMainLoop::BrowserThreadsStarted, base::Unretained(this));
+    startup_task_runner_->AddTask(browser_thread_started);
 
-  StartupTask pre_main_message_loop_run = base::Bind(
-      &BrowserMainLoop::PreMainMessageLoopRun, base::Unretained(this));
-  task_runner->AddTask(pre_main_message_loop_run);
+    StartupTask pre_main_message_loop_run = base::Bind(
+        &BrowserMainLoop::PreMainMessageLoopRun, base::Unretained(this));
+    startup_task_runner_->AddTask(pre_main_message_loop_run);
 
-  task_runner->StartRunningTasks();
+#if defined(OS_ANDROID)
+    if (BrowserMayStartAsynchronously()) {
+      startup_task_runner_->StartRunningTasksAsync();
+    }
+#endif
+  }
+#if defined(OS_ANDROID)
+  if (!BrowserMayStartAsynchronously()) {
+    // A second request for asynchronous startup can be ignored, so
+    // StartupRunningTasksAsync is only called first time through. If, however,
+    // this is a request for synchronous startup then it must override any
+    // previous call for async startup, so we call RunAllTasksNow()
+    // unconditionally.
+    startup_task_runner_->RunAllTasksNow();
+  }
+#else
+  startup_task_runner_->RunAllTasksNow();
+#endif
 }
 
 int BrowserMainLoop::CreateThreads() {