Enable asynchronous glReadPixels on Windows.

gpu/command_buffer/client/gles2_implementation_unittest.cc

Index: gpu/command_buffer/client/gles2_implementation_unittest.cc
diff --git a/gpu/command_buffer/client/gles2_implementation_unittest.cc b/gpu/command_buffer/client/gles2_implementation_unittest.cc
index 799618cb4d795512090201aa20550e3feb8cae11..70a09adb32d632305751a66f90b32cf07525b308 100644
--- a/gpu/command_buffer/client/gles2_implementation_unittest.cc
+++ b/gpu/command_buffer/client/gles2_implementation_unittest.cc
@@ -1676,8 +1676,8 @@ TEST_F(GLES2ImplementationTest, ReadPixels2Reads) {
   scoped_ptr<int8[]> buffer(new int8[kWidth * kHeight * kBytesPerPixel]);
 
   EXPECT_CALL(*command_buffer(), OnFlush())
-      .WillOnce(SetMemory(result1.ptr, static_cast<uint32>(1)))
-      .WillOnce(SetMemory(result2.ptr, static_cast<uint32>(1)))
+      .WillOnce(SetMemory(result1.ptr, static_cast<uint32>(GL_NO_ERROR)))
+      .WillOnce(SetMemory(result2.ptr, static_cast<uint32>(GL_NO_ERROR)))
       .RetiresOnSaturation();
 
   gl_->ReadPixels(0, 0, kWidth, kHeight, kFormat, kType, buffer.get());
@@ -1708,12 +1708,52 @@ TEST_F(GLES2ImplementationTest, ReadPixelsBadFormatType) {
   scoped_ptr<int8[]> buffer(new int8[kWidth * kHeight * kBytesPerPixel]);
 
   EXPECT_CALL(*command_buffer(), OnFlush())
-      .Times(1)
+      .WillOnce(SetMemory(result1.ptr,
+                          static_cast<uint32>(GL_INVALID_ENUM)))
       .RetiresOnSaturation();
 
   gl_->ReadPixels(0, 0, kWidth, kHeight, kFormat, kType, buffer.get());
 }
 
+TEST_F(GLES2ImplementationTest, MapBufferErrorPropagation) {
+  const GLsizeiptr kBufferSize = 64;
+
+  // Create a buffer for readback purposes.
+  GLuint buffer = 0;
+  gl_->GenBuffers(1, &buffer);
+  gl_->BindBuffer(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM, buffer);
+  gl_->BufferData(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM,
+                  kBufferSize,
+                  NULL,
+                  GL_STREAM_READ);
+
+  // Expect to successfully map the buffer that was just created.
+  EXPECT_CALL(*command_buffer(), OnFlush())
+      .Times(1)
+      .RetiresOnSaturation();
+  void* data = gl_->MapBufferCHROMIUM(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM,
+                                      GL_READ_ONLY);
+  EXPECT_TRUE(data);
+  gl_->UnmapBufferCHROMIUM(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM);
+
+  // Simulate the service encountering a GL_OUT_OF_MEMORY error during a
+  // readback into the service-side buffer.  The GL error code is internally
+  // stored in the 4 bytes following the end of the buffer.
+  *(reinterpret_cast<uint32_t*>(static_cast<uint8_t*>(data) + kBufferSize)) =
+      GL_OUT_OF_MEMORY;
+
+  // Now, try to map the buffer again and expect failure.
+  data = gl_->MapBufferCHROMIUM(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM,
+                                GL_READ_ONLY);
+  EXPECT_FALSE(data);
+  EXPECT_EQ(GL_OUT_OF_MEMORY, gl_->GetError());
+
+  // Clean up.
+  gl_->UnmapBufferCHROMIUM(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM);
+  gl_->BindBuffer(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM, 0);
+  gl_->DeleteBuffers(1, &buffer);
+}
+
 TEST_F(GLES2ImplementationTest, FreeUnusedSharedMemory) {
   struct Cmds {
     cmds::BufferSubData buf;