Move Context draw call logic into RendererD3D.

Also move a lot of supporting code.

BUG=angle:789

Change-Id: I098bf7d072ece1f414605783c32ec5354ba63e19
Reviewed-on: https://chromium-review.googlesource.com/226061
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
diff --git a/src/libGLESv2/ResourceManager.cpp b/src/libGLESv2/ResourceManager.cpp
index 0a9c3d3..ac6a0a2 100644
--- a/src/libGLESv2/ResourceManager.cpp
+++ b/src/libGLESv2/ResourceManager.cpp
@@ -295,9 +295,9 @@
     }
 }
 
-Program *ResourceManager::getProgram(unsigned int handle)
+Program *ResourceManager::getProgram(unsigned int handle) const
 {
-    ProgramMap::iterator program = mProgramMap.find(handle);
+    ProgramMap::const_iterator program = mProgramMap.find(handle);
 
     if (program == mProgramMap.end())
     {