gpu: Compositor management of GpuMemoryBuffer instances.

ui/gl/gl_image_shared_memory.cc

Index: ui/gl/gl_image_shared_memory.cc
diff --git a/ui/gl/gl_image_shared_memory.cc b/ui/gl/gl_image_shared_memory.cc
index 7c615f8efabc9f191267995c96b1a55092799d04..4aa255b03df7edb15b46936eba3af6bf5df3da3a 100644
--- a/ui/gl/gl_image_shared_memory.cc
+++ b/ui/gl/gl_image_shared_memory.cc
@@ -18,10 +18,8 @@ GLImageSharedMemory::~GLImageSharedMemory() {
   DCHECK(!shared_memory_);
 }
 
-bool GLImageSharedMemory::Initialize(const gfx::GpuMemoryBufferHandle& handle) {
-  if (!HasValidFormat())
-    return false;
-
+bool GLImageSharedMemory::Initialize(const gfx::GpuMemoryBufferHandle& handle,
+                                     gfx::GpuMemoryBuffer::Format format) {
   if (!base::SharedMemory::IsHandleValid(handle.handle))
     return false;
 
@@ -37,16 +35,18 @@ bool GLImageSharedMemory::Initialize(const gfx::GpuMemoryBufferHandle& handle) {
 
   scoped_ptr<base::SharedMemory> duped_shared_memory(
       new base::SharedMemory(duped_shared_memory_handle, true));
-
-  if (!duped_shared_memory->Map(Bytes())) {
+  if (!duped_shared_memory->Map(GetSize().GetArea() * BytesPerPixel(format))) {

[piman, 2014/10/09 21:33:02]

We should avoid GetSize().GetArea() * BytesPerPixel(format) because of potential
for overflow. We can use CheckedNumeric types like in e.g.
SharedBitmap::CheckedSizeInBytes to be safe (I realize you're just moving code,
but catching this now).

[reveman, 2014/10/10 02:20:16]

Done.

     DVLOG(0) << "Failed to map shared memory.";
     return false;
   }
 
+  if (!GLImageMemory::Initialize(
+          static_cast<unsigned char*>(duped_shared_memory->memory()), format)) {
+    return false;
+  }
+
   DCHECK(!shared_memory_);
   shared_memory_ = duped_shared_memory.Pass();
-  GLImageMemory::Initialize(
-      static_cast<unsigned char*>(shared_memory_->memory()));
   return true;
 }