Don't block 3D apis if GPU process shut down was expected

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index ef4fea313dffd423a165ce15f1f8a23bed1cf374..bea5caed94d5471c1ef68fb8cd0bde5d1715829c 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -451,11 +451,6 @@ GpuProcessHost::~GpuProcessHost() {
   if (g_gpu_process_hosts[kind_] == this)
     g_gpu_process_hosts[kind_] = NULL;
 
-  // If there are any remaining offscreen contexts at the point the
-  // GPU process exits, assume something went wrong, and block their
-  // URLs from accessing client 3D APIs without prompting.
-  BlockLiveOffscreenContexts();
-
   UMA_HISTOGRAM_COUNTS_100("GPU.AtExitSurfaceCount",
                            GpuSurfaceTracker::Get()->GetSurfaceCount());
   UMA_HISTOGRAM_BOOLEAN("GPU.AtExitReceivedMemoryStats",
@@ -473,6 +468,7 @@ GpuProcessHost::~GpuProcessHost() {
   }
 
   std::string message;
+  bool block_offscreen_contexts = true;
   if (!in_process_) {
     int exit_code;
     base::TerminationStatus status = process_->GetTerminationStatus(
@@ -490,6 +486,13 @@ GpuProcessHost::~GpuProcessHost() {
 
     switch (status) {
       case base::TERMINATION_STATUS_NORMAL_TERMINATION:
+#if defined(OS_ANDROID)

[no sievers, 2016/03/01 23:04:34]

I'm wondering if this even needs the ifdef Android.

Also, CrOS also has an OOM killer right?

+piman

[Ken Russell (switch to Gerrit), 2016/03/02 00:48:47]

You're right, it's probably not needed. The only time this code path tends to be
taken on other platforms, as far as I know, is when about:gpu is visited and
that triggers a launch of a temporary GPU process for information gathering
purposes.
I'm not sure CrOS would ever kill the GPU process though. The entire UI is
predicated on the GPU process staying alive.

+        // Don't block offscreen contexts (and force page reload for webgl)
+        // if we might have gotten killed by the OOM killer.
+        // Note that NORMAL_TERMINATION here implies that the browser
+        // was backgrounded (or we'd be TERMINATION_STATUS_OOM_PROTECTED).
+        block_offscreen_contexts = false;
+#endif
         message = "The GPU process exited normally. Everything is okay.";
         break;
       case base::TERMINATION_STATUS_ABNORMAL_TERMINATION:
@@ -516,6 +519,12 @@ GpuProcessHost::~GpuProcessHost() {
     }
   }
 
+  // If there are any remaining offscreen contexts at the point the
+  // GPU process exits, assume something went wrong, and block their
+  // URLs from accessing client 3D APIs without prompting.
+  if (block_offscreen_contexts)
+    BlockLiveOffscreenContexts();
+
   BrowserThread::PostTask(BrowserThread::UI,
                           FROM_HERE,
                           base::Bind(&GpuProcessHostUIShim::Destroy,