Change Map() API to take in a mode for read/write/read-or-write, also pass gfx::Size by value as for small structs it's more efficient.

BUG=175012


Review URL: https://chromiumcodereview.appspot.com/13879002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193234 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 9 insertions, 4 deletions

diff --git a/ui/gl/gpu_memory_buffer.h b/ui/gl/gpu_memory_buffer.h
index 2e24903..403c278 100644
--- a/ui/gl/gpu_memory_buffer.h
+++ b/ui/gl/gpu_memory_buffer.h
@@ -18,12 +18,17 @@ class Size;
 //
 // THREADING CONSIDERATIONS:
 //
-// This interface is thread-safe. However, multiple threads calling
-// MapForWrite() simultaneously may result in undefined behavior
-// and is not allowed.
+// This interface is thread-safe. However, multiple threads mapping
+// a buffer for Write or ReadOrWrite simultaneously may result in undefined
+// behavior and is not allowed.
 class GpuMemoryBuffer {
  public:
   typedef base::Callback<scoped_ptr<gfx::GpuMemoryBuffer>(gfx::Size)> Create;
+  enum AccessMode {
+    READ_ONLY,
+    WRITE_ONLY,
+    READ_OR_WRITE,
+  };
 
   // Frees a previously allocated buffer. Freeing a buffer that is still
   // mapped in any process is undefined behavior.
@@ -32,7 +37,7 @@ class GpuMemoryBuffer {
   // Maps the buffer so the client can write the bitmap data in |*vaddr|
   // subsequently. This call may block, for instance if the hardware needs
   // to finish rendering or if CPU caches need to be synchronized.
-  virtual void MapForWrite(void** vaddr) = 0;
+  virtual void Map(AccessMode mode, void** vaddr) = 0;
 
   // Unmaps the buffer. Called after all changes to the buffer are
   // completed.