Fix the issue that it may get wrong stride in cc::ResourceProvider::MapImage.

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 348516da7ddae34b11eace46c45a6251dfb2f221..16f8b7edcd98c7eef5490b3424103b7bdde86e42 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -3908,6 +3908,12 @@ void GLES2Implementation::GetImageParameterivCHROMIUMHelper(
     return;
   }
 
+  if (!gpu_buffer->IsMapped()) {
+    SetGLError(GL_INVALID_OPERATION, "glGetImageParameterivCHROMIUM",
+      "MapImageCHROMIUM should be called prior to GetImageParameterivCHROMIUM");

[reveman, 2014/03/04 15:17:31]

nit: "not mapped" is enough. also please use "git cl format" to make sure this
is formatted correctly.

[junj, 2014/03/05 07:50:57]

Done.

+    return;
+  }
+
   *params = gpu_buffer->GetStride();
 }