Add PERSISTENT_MAP usage for GpuMemoryBuffers.

content/browser/gpu/browser_gpu_memory_buffer_manager.cc

Index: content/browser/gpu/browser_gpu_memory_buffer_manager.cc
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
index 70184a0f48aeb2218554e36f37314ed2ba6854ac..564a0b79ef09ec6e06a4f340b41e4f70d0b891a7 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
@@ -100,7 +100,9 @@ BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferCommon(
   if (!gpu_memory_buffer_factory_host_->IsGpuMemoryBufferConfigurationSupported(
           format, usage)) {
     DCHECK(GpuMemoryBufferImplSharedMemory::IsFormatSupported(format));
-    DCHECK_EQ(usage, gfx::GpuMemoryBuffer::MAP);
+    DCHECK(usage == gfx::GpuMemoryBuffer::MAP ||
+           usage == gfx::GpuMemoryBuffer::PERSISTENT_MAP)
+        << usage;

[reveman, 2015/05/19 16:12:12]

Do you mind adding a GpuMemoryBufferImplSharedMemory::IsUsageSupported function
to clean this up a bit?

[danakj, 2015/05/19 22:19:43]

Done.

     return GpuMemoryBufferImplSharedMemory::Create(
         g_next_gpu_memory_buffer_id.GetNext(), size, format);
   }
@@ -142,8 +144,12 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForChildProcess(
           format, usage)) {
     // Early out if we cannot fallback to shared memory buffer.
     if (!GpuMemoryBufferImplSharedMemory::IsFormatSupported(format) ||
-        !GpuMemoryBufferImplSharedMemory::IsSizeValidForFormat(size, format) ||
-        usage != gfx::GpuMemoryBuffer::MAP) {
+        !GpuMemoryBufferImplSharedMemory::IsSizeValidForFormat(size, format)) {
+      callback.Run(gfx::GpuMemoryBufferHandle());
+      return;
+    }
+    if (usage != gfx::GpuMemoryBuffer::MAP &&
+        usage != gfx::GpuMemoryBuffer::PERSISTENT_MAP) {
       callback.Run(gfx::GpuMemoryBufferHandle());
       return;
     }