Switch to prebuilt bison

Now we have prebuilt bison 2.7 for both Linux and Mac OS X.
We don't need the LOCAL_BISON or LOCAL_YACC any more.

Bug: 8517572
Change-Id: I11319b7e154bbfe6355c98bd1d7f5f22ed727f85
Disable OES_texture_float WebGL extension

The following WebGL 1.0.2 conformance tests are causing crashes in
WebGLRenderingContext::texImage2DImpl:

conformance/extensions/oes-texture-float-with-canvas.html
conformance/extensions/oes-texture-float-with-image-data.html
conformance/extensions/oes-texture-float-with-image.html

Turning off the extension to avoid crashing.

Change-Id: Ideaf118cbd4770cd3b1f677bf342d9cc802a6688
CRs-fixed: 427617
Build fix with newer bison 2.6

From: http://trac.webkit.org/changeset/124099

Bug: 8517572
Change-Id: Iaead93f01d6a86180c21e320ef56a4620619ce00
Use combined depth and stencil buffers

Use combined depth and stencil buffers when both are requested together.
When stencil and depth buffers are requested, create a packed buffer
instead of standalone buffers and attach it to both the DEPTH_ATTACHMENT
point as well as the STENCIL_ATTACHMENT point as per
OES_packed_depth_stencil extension to GLES2.

CRs-fixed: 45920

Change-Id: I537efb611158935206c295fec8fc1a9b6d27e82b
Tweaks for forward compatibility

Change-Id: I136fcbbc14072ee5f5281d09445f28d083ed3ce1
Enable Webworkers and GC fix

Cherrypicked from Iad989ce9378c24e250827533cfc698f2e76c3be7 (#/c/157027)

Change-Id: Ib779906e3354bb541d47c7f1096e3faa611c65a7
 networking features:

        - memory cache
        - request queue priority
        - event collection mechanism
      - merging new stathub interface changes

Change-Id: I2f3fa2effb49c2050f6b6b991a9b1f0d4b692849
webkit: Fix build in ISO C++ 11 mode

Change-Id: I32b3121ae46678f847dcd74ea74484aaf8f34eaf
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
Fix compilation warning for list of initialization constructor arguments
after bae7aeaa87.

Change-Id: I75716404cfeb76d2d79efb94c82d57345e3e9932
Fix leak of inspectorClient when INSPECTOR disabled

WebKit PageClient api has undefined memory management. It seems
to take custody of the parameters only if it wants to use it.
Thus, only allocate inspectorClient if needed.

Change-Id: Ibae7e683ec0c9553845c482b52dab7fad94e4398