Add texture filtering precision hint

A new extension will be added to SwiftShader in order to allow
Chromium to trigger high precision filtering when necessary.
This extension is documented in:
extensions/CHROMIUM_texture_filtering_hint.txt

Bug swiftshader:76

Change-Id: I7c5b5c5fd01afbd7079e7949ecbd9c18fc539f2b
Reviewed-on: https://swiftshader-review.googlesource.com/10708
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/Renderer/Renderer.cpp

diff --git a/src/Renderer/Renderer.cpp b/src/Renderer/Renderer.cpp
index a84423d..a67ba22 100644
--- a/src/Renderer/Renderer.cpp
+++ b/src/Renderer/Renderer.cpp
@@ -2314,6 +2314,18 @@
 		}
 	}
 
+	void Renderer::setHighPrecisionFiltering(SamplerType type, int sampler, bool highPrecisionFiltering)
+	{
+		if(type == SAMPLER_PIXEL)
+		{
+			PixelProcessor::setHighPrecisionFiltering(sampler, highPrecisionFiltering);
+		}
+		else
+		{
+			VertexProcessor::setHighPrecisionFiltering(sampler, highPrecisionFiltering);
+		}
+	}
+
 	void Renderer::setSwizzleR(SamplerType type, int sampler, SwizzleType swizzleR)
 	{
 		if(type == SAMPLER_PIXEL)