Make tracing work on Android

sky/tools/debugger/prompt/prompt.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <algorithm>
+
 #include "base/bind.h"
+#include "base/files/file_path.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "mojo/application/application_runner_chromium.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
 #include "net/base/net_errors.h"
 #include "net/server/http_server.h"
 #include "net/server/http_server_request_info.h"
 #include "net/socket/tcp_server_socket.h"
 #include "services/tracing/tracing.mojom.h"
 #include "sky/tools/debugger/debugger.mojom.h"
+#include "sky/tools/debugger/prompt/trace_collector.h"
 
 namespace sky {
 namespace debugger {
+namespace {
 
-class Prompt : public mojo::ApplicationDelegate, public net::HttpServer::Delegate {
+const size_t kMinSendBufferSize = 1024 * 1024;
+}
+
+class Prompt : public mojo::ApplicationDelegate,
+               public net::HttpServer::Delegate {
  public:
   Prompt()
       : is_tracing_(false),
         weak_ptr_factory_(this) {
   }
   virtual ~Prompt() {
   }
 
  private:
   // Overridden from mojo::ApplicationDelegate:
@@ skipping 57 matching lines @@
       int connection_id, const net::HttpServerRequestInfo& info) override {
     web_server_->Send500(connection_id, "http only");
   }
 
   void OnWebSocketMessage(
       int connection_id, const std::string& data) override {
     web_server_->Send500(connection_id, "http only");
   }
 
   void Respond(int connection_id, std::string response) {
+    web_server_->SetSendBufferSize(

[eseidel, 2015/01/16 00:07:25]

You should expain why you're donig this in a comment.

[abarth-chromium, 2015/01/16 00:31:53]

Done.

+        connection_id, std::max(kMinSendBufferSize, response.length()));
     web_server_->Send200(connection_id, response, "text/plain");
   }
 
   void Help(std::string path, int connection_id) {
     std::string help = base::StringPrintf("Sky Debugger running on port %d\n"
         "Supported URLs:\n"
         "/toggle_tracing   -- Start/stop tracing\n"
         "/reload           -- Reload the current page\n"
         "/inspect          -- Start inspector server for current page\n"
         "/quit             -- Quit\n"
@@ skipping 20 matching lines @@
     Respond(connection_id,
         "Open the following URL in Chrome:\n"
         "chrome-devtools://devtools/bundled/devtools.html?ws=localhost:9898\n");
   }
 
   void Quit(int connection_id) {
     debugger_->Shutdown();
   }
 
   void ToggleTracing(int connection_id) {
-    std::string response;
-    if (is_tracing_) {
-      response = "Stopping trace (writing to sky_viewer.trace)\n";
+    bool was_tracing = is_tracing_;
+    is_tracing_ = !is_tracing_;
+
+    if (was_tracing) {
       tracing_->StopAndFlush();
-    } else {
-      response = "Starting trace (type 'trace' to stop tracing)\n";
-      tracing_->Start(mojo::String("sky_viewer"), mojo::String("*"));
+      trace_collector_->GetTrace(base::Bind(
+          &Prompt::OnTraceAvailable, base::Unretained(this), connection_id));
+      return;
     }
-    is_tracing_ = !is_tracing_;
-    Respond(connection_id, response);
+
+    mojo::DataPipe pipe;
+    tracing_->Start(pipe.producer_handle.Pass(), mojo::String("*"));
+    trace_collector_.reset(new TraceCollector(pipe.consumer_handle.Pass()));
+    Respond(connection_id, "Starting trace (type 'trace' to stop tracing)\n");
+  }
+
+  void OnTraceAvailable(int connection_id, std::string trace) {
+    trace_collector_.reset();
+    Respond(connection_id, trace);
   }
 
   bool is_tracing_;
   DebuggerPtr debugger_;
   tracing::TraceCoordinatorPtr tracing_;
   std::string url_;
   base::WeakPtrFactory<Prompt> weak_ptr_factory_;
   scoped_ptr<net::HttpServer> web_server_;
   uint32_t command_port_;
 
+  scoped_ptr<TraceCollector> trace_collector_;
+
   DISALLOW_COPY_AND_ASSIGN(Prompt);
 };
 
 }  // namespace debugger
 }  // namespace sky
 
 MojoResult MojoMain(MojoHandle shell_handle) {
   mojo::ApplicationRunnerChromium runner(new sky::debugger::Prompt);
   runner.set_message_loop_type(base::MessageLoop::TYPE_IO);
   return runner.Run(shell_handle);
 }