8 files changed, 28 insertions, 2 deletions
diff --git a/chrome/browser/browser_about_handler.cc b/chrome/browser/browser_about_handler.cc
index 4406a31..69ad244 100644
--- a/chrome/browser/browser_about_handler.cc
+++ b/chrome/browser/browser_about_handler.cc
@@ -271,7 +271,7 @@ std::string AboutAbout() {
     html.append(kAllAboutPaths[i]);
     html.append("</a>\n");
   }
-  const char *debug[] = { "crash", "hang", "shorthang", "gpucrash" };
+  const char *debug[] = { "crash", "hang", "shorthang", "gpucrash", "gpuhang" };
   html.append("</ul><h2>For Debug</h2>");
   html.append("</ul><p>The following pages are for debugging purposes only. "
               "Because they crash or hang the renderer, they're not linked "
@@ -1160,11 +1160,15 @@ bool WillHandleBrowserAboutURL(GURL* url, Profile* profile) {
     return true;
   }
 
-  // Handle URL to crash the gpu process.
+  // Handle URLs to wreck the gpu process.
   if (LowerCaseEqualsASCII(url->spec(), chrome::kAboutGpuCrashURL)) {
     GpuProcessHost::SendAboutGpuCrash();
     return true;
   }
+  if (LowerCaseEqualsASCII(url->spec(), chrome::kAboutGpuHangURL)) {
+    GpuProcessHost::SendAboutGpuHang();
+    return true;
+  }
 
   // There are a few about: URLs that we hand over to the renderer. If the
   // renderer wants them, don't do any rewriting.
diff --git a/chrome/browser/gpu_process_host.cc b/chrome/browser/gpu_process_host.cc
index f2bba1f..f4c6164 100644
--- a/chrome/browser/gpu_process_host.cc
+++ b/chrome/browser/gpu_process_host.cc
@@ -127,6 +127,11 @@ void GpuProcessHost::SendAboutGpuCrash() {
   Get()->Send(new GpuMsg_Crash());
 }
 
+// static
+void GpuProcessHost::SendAboutGpuHang() {
+  Get()->Send(new GpuMsg_Hang());
+}
+
 bool GpuProcessHost::Send(IPC::Message* msg) {
   if (!EnsureInitialized())
     return false;
diff --git a/chrome/browser/gpu_process_host.h b/chrome/browser/gpu_process_host.h
index d885408..e4d4559 100644
--- a/chrome/browser/gpu_process_host.h
+++ b/chrome/browser/gpu_process_host.h
@@ -31,6 +31,10 @@ class GpuProcessHost : public BrowserChildProcessHost {
   // Tells the GPU process to crash. Useful for testing.
   static void SendAboutGpuCrash();
 
+  // Tells the GPU process to let its main thread enter an infinite loop.
+  // Useful for testing.
+  static void SendAboutGpuHang();
+
   // Shutdown routine, which should only be called upon process
   // termination.
   static void Shutdown();
diff --git a/chrome/common/gpu_messages_internal.h b/chrome/common/gpu_messages_internal.h
index 229e3db..0121e16 100644
--- a/chrome/common/gpu_messages_internal.h
+++ b/chrome/common/gpu_messages_internal.h
@@ -53,6 +53,9 @@ IPC_BEGIN_MESSAGES(Gpu)
   // Tells the GPU process to crash.
   IPC_MESSAGE_CONTROL0(GpuMsg_Crash)
 
+  // Tells the GPU process to hang.
+  IPC_MESSAGE_CONTROL0(GpuMsg_Hang)
+
   // Creates a new backing store.
   IPC_MESSAGE_ROUTED2(GpuMsg_NewBackingStore,
                       int32, /* backing_store_routing_id */
diff --git a/chrome/common/url_constants.cc b/chrome/common/url_constants.cc
index 5ae5181..8a119f9 100644
--- a/chrome/common/url_constants.cc
+++ b/chrome/common/url_constants.cc
@@ -50,6 +50,7 @@ const char kAboutCrashURL[] = "about:crash";
 const char kAboutCreditsURL[] = "about:credits";
 const char kAboutDNSURL[] = "about:dns";
 const char kAboutGpuCrashURL[] = "about:gpucrash";
+const char kAboutGpuHangURL[] = "about:gpuhang";
 const char kAboutHangURL[] = "about:hang";
 const char kAboutHistogramsURL[] = "about:histograms";
 const char kAboutLabsURL[] = "about:labs";
diff --git a/chrome/common/url_constants.h b/chrome/common/url_constants.h
index cd2f889..b665550 100644
--- a/chrome/common/url_constants.h
+++ b/chrome/common/url_constants.h
@@ -45,6 +45,7 @@ extern const char kAboutCrashURL[];
 extern const char kAboutCreditsURL[];
 extern const char kAboutDNSURL[];
 extern const char kAboutGpuCrashURL[];
+extern const char kAboutGpuHangURL[];
 extern const char kAboutHangURL[];
 extern const char kAboutHistogramsURL[];
 extern const char kAboutLabsURL[];
diff --git a/chrome/gpu/gpu_thread.cc b/chrome/gpu/gpu_thread.cc
index 97cb5d1..cb2a89b 100644
--- a/chrome/gpu/gpu_thread.cc
+++ b/chrome/gpu/gpu_thread.cc
@@ -91,6 +91,8 @@ void GpuThread::OnControlMessageReceived(const IPC::Message& msg) {
                         OnCollectGraphicsInfo)
     IPC_MESSAGE_HANDLER(GpuMsg_Crash,
                         OnCrash)
+    IPC_MESSAGE_HANDLER(GpuMsg_Hang,
+                        OnHang)
   IPC_END_MESSAGE_MAP_EX()
 }
 
@@ -168,3 +170,8 @@ void GpuThread::OnCrash() {
   volatile int* it_s_the_end_of_the_world_as_we_know_it = NULL;
   *it_s_the_end_of_the_world_as_we_know_it = 0xdead;
 }
+
+void GpuThread::OnHang() {
+  for (;;)
+    PlatformThread::Sleep(1000);
+}
diff --git a/chrome/gpu/gpu_thread.h b/chrome/gpu/gpu_thread.h
index 519b092..b896360 100644
--- a/chrome/gpu/gpu_thread.h
+++ b/chrome/gpu/gpu_thread.h
@@ -43,6 +43,7 @@ class GpuThread : public ChildThread {
   void OnSynchronize();
   void OnCollectGraphicsInfo();
   void OnCrash();
+  void OnHang();
   void OnNewRenderWidgetHostView(GpuNativeWindowHandle parent_window,
                                  int32 routing_id);