DevTools: process pause script request on the IO thread. To pause already running script we need to call v8::Debug::DebugBreak() on a thread different from the Render thread which may be busy with JS execution.

BUG=28892
TEST=DevToolsSanityTest.TestPauseWhenScriptIsRunning

Review URL: http://codereview.chromium.org/444017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33279 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 47 insertions, 12 deletions

diff --git a/chrome/browser/debugger/devtools_sanity_unittest.cc b/chrome/browser/debugger/devtools_sanity_unittest.cc
index 405d809..3c3b8d4 100644
--- a/chrome/browser/debugger/devtools_sanity_unittest.cc
+++ b/chrome/browser/debugger/devtools_sanity_unittest.cc
@@ -53,6 +53,8 @@ const wchar_t kPauseOnExceptionTestPage[] =
     L"files/devtools/pause_on_exception.html";
 const wchar_t kPauseWhenLoadingDevTools[] =
     L"files/devtools/pause_when_loading_devtools.html";
+const wchar_t kPauseWhenScriptIsRunning[] =
+    L"files/devtools/pause_when_script_is_running.html";
 const wchar_t kResourceContentLengthTestPage[] = L"files/devtools/image.html";
 const wchar_t kResourceTestPage[] = L"files/devtools/resource_test_page.html";
 const wchar_t kSimplePage[] = L"files/devtools/simple_page.html";
@@ -344,6 +346,12 @@ IN_PROC_BROWSER_TEST_F(DevToolsSanityTest, TestPauseWhenLoadingDevTools) {
   RunTest("testPauseWhenLoadingDevTools", kPauseWhenLoadingDevTools);
 }
 
+// Tests that pressing 'Pause' will pause script execution if the script
+// is already running.
+IN_PROC_BROWSER_TEST_F(DevToolsSanityTest, TestPauseWhenScriptIsRunning) {
+  RunTest("testPauseWhenScriptIsRunning", kPauseWhenScriptIsRunning);
+}
+
 // Tests eval on call frame.
 IN_PROC_BROWSER_TEST_F(DevToolsSanityTest, TestEvalOnCallFrame) {
   RunTest("testEvalOnCallFrame", kDebuggerTestPage);
diff --git a/chrome/common/devtools_messages_internal.h b/chrome/common/devtools_messages_internal.h
index be187a7..d80c0ed 100644
--- a/chrome/common/devtools_messages_internal.h
+++ b/chrome/common/devtools_messages_internal.h
@@ -86,6 +86,12 @@ IPC_BEGIN_MESSAGES(DevToolsAgent)
   IPC_MESSAGE_CONTROL1(DevToolsAgentMsg_DebuggerCommand,
                        std::string  /* command */)
 
+  // This command is sent to debugger when user wants to pause script execution
+  // immediately. This message should be processed on the IO thread so that it
+  // can have effect even if the Renderer thread is busy with JavaScript
+  // execution.
+  IPC_MESSAGE_CONTROL0(DevToolsAgentMsg_DebuggerPauseScript)
+
   // Inspect element with the given coordinates.
   IPC_MESSAGE_CONTROL2(DevToolsAgentMsg_InspectElement,
                        int /* x */,
diff --git a/chrome/renderer/devtools_agent_filter.cc b/chrome/renderer/devtools_agent_filter.cc
index f67f183..93b6c75 100644
--- a/chrome/renderer/devtools_agent_filter.cc
+++ b/chrome/renderer/devtools_agent_filter.cc
@@ -34,21 +34,23 @@ DevToolsAgentFilter::~DevToolsAgentFilter() {
 }
 
 bool DevToolsAgentFilter::OnMessageReceived(const IPC::Message& message) {
-  if (message.type() == DevToolsAgentMsg_DebuggerCommand::ID) {
-    // Dispatch command directly from IO.
-    bool handled = true;
-    current_routing_id_ = message.routing_id();
-    IPC_BEGIN_MESSAGE_MAP(DevToolsAgentFilter, message)
-      IPC_MESSAGE_HANDLER(DevToolsAgentMsg_DebuggerCommand, OnDebuggerCommand)
-      IPC_MESSAGE_UNHANDLED(handled = false)
-    IPC_END_MESSAGE_MAP()
-    return handled;
-  } else {
-    return false;
-  }
+  // Dispatch debugger commands directly from IO.
+  bool handled = true;
+  current_routing_id_ = message.routing_id();
+  IPC_BEGIN_MESSAGE_MAP(DevToolsAgentFilter, message)
+    IPC_MESSAGE_HANDLER(DevToolsAgentMsg_DebuggerCommand, OnDebuggerCommand)
+    IPC_MESSAGE_HANDLER(DevToolsAgentMsg_DebuggerPauseScript,
+                        OnDebuggerPauseScript)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
 }
 
 void DevToolsAgentFilter::OnDebuggerCommand(const std::string& command) {
   WebDevToolsAgent::executeDebuggerCommand(
       WebString::fromUTF8(command), current_routing_id_);
 }
+
+void DevToolsAgentFilter::OnDebuggerPauseScript() {
+  WebDevToolsAgent::debuggerPauseScript();
+}
diff --git a/chrome/renderer/devtools_agent_filter.h b/chrome/renderer/devtools_agent_filter.h
index 9ee6296..4bf4460 100644
--- a/chrome/renderer/devtools_agent_filter.h
+++ b/chrome/renderer/devtools_agent_filter.h
@@ -31,6 +31,7 @@ class DevToolsAgentFilter : public IPC::ChannelProxy::MessageFilter {
   // OnDebuggerCommand will be executed in the IO thread so that we can
   // handle debug messages even when v8 is stopped.
   void OnDebuggerCommand(const std::string& command);
+  void OnDebuggerPauseScript();
 
   int current_routing_id_;
 
diff --git a/chrome/renderer/devtools_client.cc b/chrome/renderer/devtools_client.cc
index 9b17c8b..8083288 100644
--- a/chrome/renderer/devtools_client.cc
+++ b/chrome/renderer/devtools_client.cc
@@ -64,6 +64,10 @@ void DevToolsClient::sendDebuggerCommandToAgent(const WebString& command) {
   Send(DevToolsAgentMsg_DebuggerCommand(command.utf8()));
 }
 
+void DevToolsClient::sendDebuggerPauseScript() {
+  Send(DevToolsAgentMsg_DebuggerPauseScript());
+}
+
 void DevToolsClient::activateWindow() {
   render_view_->Send(new ViewHostMsg_ActivateDevToolsWindow(
       render_view_->routing_id()));
diff --git a/chrome/renderer/devtools_client.h b/chrome/renderer/devtools_client.h
index e83ec12..aad5c09 100644
--- a/chrome/renderer/devtools_client.h
+++ b/chrome/renderer/devtools_client.h
@@ -43,6 +43,7 @@ class DevToolsClient : public WebKit::WebDevToolsFrontendClient {
                                   const WebKit::WebString& param2,
                                   const WebKit::WebString& param3);
   virtual void sendDebuggerCommandToAgent(const WebKit::WebString& command);
+  virtual void sendDebuggerPauseScript();
 
   virtual void activateWindow();
   virtual void closeWindow();
diff --git a/chrome/test/data/devtools/pause_when_script_is_running.html b/chrome/test/data/devtools/pause_when_script_is_running.html
new file mode 100644
index 0000000..380d8e1
--- /dev/null
+++ b/chrome/test/data/devtools/pause_when_script_is_running.html
@@ -0,0 +1,13 @@
+<html>
+<head>
+<script>
+function handleClick() {
+  while(true) {
+  }
+}
+</script>
+</head>
+<body>
+<input type='button' onclick='handleClick()' value='Test'/>
+</body>
+</html>
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