Use code generator's argument processing in custom WebGL methods

Use code generator's argument processing in custom WebGL methods

The argument handling in these methods is not special, it's typically
their return values that need custom code, so align the argument
processing with what the code generator would have done.

This was done by temporarily dropping the [Custom] on these methods, and
then simply copy the corresponding blocks of code from the generated
methods.

This fixes exception handling in some cases where argument conversion
failed, for instance if getFramebufferAttachmentParameter() was called
with an object as the first argument, and that object had a valueOf()
function that threw an exception. The old custom code would simply
ignore that exception, for unknown reasons.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177946

[Jens Widell, 2014-07-11 12:24:31]

PTAL

Low-priority stuff; just some irregularities I noticed when looking at
V8WebGLRenderingContextCustom.cpp.

https://codereview.chromium.org/389583002/diff/20001/Source/bindings/core/v8/...
File Source/bindings/core/v8/custom/V8WebGLRenderingContextCustom.cpp (left):

https://codereview.chromium.org/389583002/diff/20001/Source/bindings/core/v8/...
Source/bindings/core/v8/custom/V8WebGLRenderingContextCustom.cpp:295: unsigned
target = toInt32(info[0], exceptionState);
These uses of toInt32() shared a common problem: if the V8 value is an object
whose valueOf() (or toString()) throws, that exception won't be in
exceptionState but rather it will have been re-thrown to V8 already. The "if
(exceptionState.throwIfNeeded())" below thus fails to detect that an exception
was raised.

I wonder if we should fix toInt32() so that exceptionState always contains the
exception, or if we should stop using toInt32() directly in custom code (and use
TONATIVE_* macros instead, as is changed to here.)

https://codereview.chromium.org/389583002/diff/20001/Source/core/html/canvas/...
File Source/core/html/canvas/WebGLRenderingContextBase.idl (right):

https://codereview.chromium.org/389583002/diff/20001/Source/core/html/canvas/...
Source/core/html/canvas/WebGLRenderingContextBase.idl:578: [Custom] any
getUniform(WebGLProgram? program, WebGLUniformLocation? location);
The location argument is nullable in the specification and was in our
implementation too. Change needed to get the right argument processing from the
code generator, and makes sense.

[haraken, 2014-07-11 13:41:33]

LGTM

[Jens Widell, 2014-07-11 14:41:12]

The CQ bit was checked by jl@opera.com

[commit-bot: I haz the power, 2014-07-11 14:42:22]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jl@opera.com/389583002/20001

[commit-bot: I haz the power, 2014-07-11 14:44:55]

Change committed as 177946