WebCL: Fix the build on Android 64-bits.

clGetKernelInfo() expects size_t parameters instead of cl_uint ones for
|param_value_size_ret|.

Since cl_uint is a typedef for uint32_t regardless of whether we're
building for 32 or 64 bits, the build was failing like this:

../../third_party/WebKit/Source/modules/webcl/WebCLProgram.cpp: In member function 'WTF::Vector<WTF::RefPtr<blink::WebCLKernel> > blink::WebCLProgram::createKernelsInProgram(blink::ExceptionState&)':
../../third_party/WebKit/Source/modules/webcl/WebCLProgram.cpp:262:100: error: cannot convert 'cl_uint* {aka unsigned int*}' to 'size_t* {aka long unsigned int*}' in argument passing
         err = clGetKernelInfo(kernelBuf[i], CL_KERNEL_FUNCTION_NAME, 0, nullptr, &bytesOfKernelName);
                                                                                                    ^

BUG=XWALK-3608

Author: Raphael Kubo da Costa

Source/modules/webcl/WebCLProgram.cpp

@@ -256,7 +256,7 @@ Vector<RefPtr<WebCLKernel>> WebCLProgram::createKernelsInProgram(ExceptionState&
     }
 
     Vector<char> kernelName;
-    cl_uint bytesOfKernelName = 0;
+    size_t bytesOfKernelName = 0;
     Vector<RefPtr<WebCLKernel>> m_kernelList;
     for (size_t i = 0 ; i < num; i++) {
         err = clGetKernelInfo(kernelBuf[i], CL_KERNEL_FUNCTION_NAME, 0, nullptr, &bytesOfKernelName);