Added a master switch to enable/disable gpu acceleration.

chrome/browser/gpu_process_host.cc

Index: chrome/browser/gpu_process_host.cc
===================================================================
--- chrome/browser/gpu_process_host.cc	(revision 67133)
+++ chrome/browser/gpu_process_host.cc	(working copy)
@@ -13,6 +13,7 @@
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/renderer_host/render_widget_host_view.h"
 #include "chrome/browser/renderer_host/resource_message_filter.h"
+#include "chrome/browser/tab_contents/render_view_host_delegate_helper.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/gpu_info.h"
 #include "chrome/common/gpu_messages.h"
@@ -48,6 +49,12 @@
 // initialized, the IO thread.
 static GpuProcessHost* sole_instance_ = NULL;
 
+// Number of times the gpu process has crashed in the current browser session.
+static int g_gpu_crash_count = 0;
+// Maximaum number of times the gpu process is allowed to crash in a session.

[apatrick_chromium, 2010/11/29 20:59:31]

typo: Maximum

+// Once this limit is reached, any request to launch the gpu process will fail.
+static const int kGpuMaxCrashCount = 3;
+
 void RouteOnUIThread(const IPC::Message& message) {
   BrowserThread::PostTask(BrowserThread::UI,
                           FROM_HERE,
@@ -344,13 +351,15 @@
 }
 
 void GpuProcessHost::OnProcessCrashed() {
-  // TODO(alokp): Update gpu process crash rate.
+  if (++g_gpu_crash_count >= kGpuMaxCrashCount) {
+    // The gpu process is too unstable to use. Disable it for current session.
+    RenderViewHostDelegateHelper::set_gpu_enabled(false);
+  }
   BrowserChildProcessHost::OnProcessCrashed();
 }
 
 bool GpuProcessHost::CanLaunchGpuProcess() const {
-  // TODO(alokp): Answer based on crash rate.
-  return true;
+  return RenderViewHostDelegateHelper::gpu_enabled();
 }
 
 bool GpuProcessHost::LaunchGpuProcess() {

[apatrick, 2010/11/29 17:45:38]

Does making this function return false when g_gpu_crash_count not work? It might
be that the renderer processes are not yet sufficiently robust that case but
long term that us the the plan and it would simplify this code.

[alokp, 2010/11/29 18:34:38]

yes it works and I do that too via CanLaunchGpuProcess(). Two things going on
here:
1. I am disabling gpu acceleration for all new renderer processes through a
gpu_enabled flag in RenderViewHostDelegateHelper. The command-line passed to the
new renderer process instructs it to NOT use gpu-acceleration.
2. The exisiting tabs that have crashed will try to re-launch the gpu process.
CanLaunchGpuProcess() prevents those tabs from launch the gpu-process if it is
too crashy. Now the code to relaunch the gpu process is not ready, so I am not
sure if there is a better way.