Move creation and ownership of HostZoomMap to content instead of having every embedder do this.

content/test/test_browser_context.cc

Index: content/test/test_browser_context.cc
===================================================================
--- content/test/test_browser_context.cc	(revision 122827)
+++ content/test/test_browser_context.cc	(working copy)
@@ -10,7 +10,6 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::DownloadManager;
-using content::HostZoomMap;
 
 TestBrowserContext::TestBrowserContext() {
   EXPECT_TRUE(browser_context_dir_.CreateUniqueTempDir());
@@ -54,10 +53,6 @@
   return resource_context_.get();
 }
 
-HostZoomMap* TestBrowserContext::GetHostZoomMap() {
-  return NULL;
-}
-
 content::GeolocationPermissionContext*
 TestBrowserContext::GetGeolocationPermissionContext() {
   return NULL;