Use a separate setting for CSS font inlining threshold (with a larger default),

since current for-Chrome CSS produced by fonts.g.c is quite large.

Addresses https://code.google.com/p/modpagespeed/issues/detail?id=1040
issue #1040

backported from f62b555

Author: crowell

net/instaweb/automatic/system_test.sh

@@ -296,11 +296,18 @@ fetch_until $URL 'grep -c <style' 3
 # restrictions on external connections
 if [ -z ${DISABLE_FONT_API_TESTS:-} ]; then
   test_filter inline_google_font_css Can inline Google Font API loader CSS
-  fetch_until $URL 'grep -c @font-face' 1
+  # Use a more recent version of Chrome UA than our default, which will get
+  # a very large (which hit our previous default size limits) CSS using woff2
+  WGETRC_OLD=$WGETRC
+  export WGETRC=$TESTTMP/wgetrc-chrome
+  cat > $WGETRC <<EOF
+user_agent =Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.45 Safari/537.36
+EOF
+
+  fetch_until $URL 'grep -c @font-face' 7
 
-  # By default we use a Chrome UA, so it should get woff
   OUT=$($WGET_DUMP $URL)
-  check_from "$OUT" fgrep -qi "format('woff')"
+  check_from "$OUT" fgrep -qi "format('woff2')"
   check_not_from "$OUT" fgrep -qi "format('truetype')"
   check_not_from "$OUT" fgrep -qi "format('embedded-opentype')"
   check_not_from "$OUT" fgrep -qi ".ttf"

net/instaweb/rewriter/google_font_css_inline_filter.cc

@@ -32,6 +32,8 @@ namespace net_instaweb {
 GoogleFontCssInlineFilter::GoogleFontCssInlineFilter(RewriteDriver* driver)
     : CssInlineFilter(driver) {
   set_id(RewriteOptions::kGoogleFontCssInlineId);
+  set_size_threshold_bytes(
+      driver->options()->google_font_css_inline_max_bytes());
   driver->AddResourceUrlClaimant(
       NewPermanentCallback(
           this, &GoogleFontCssInlineFilter::CheckIfFontServiceUrl));

net/instaweb/rewriter/google_font_css_inline_filter_test.cc

@@ -127,10 +127,11 @@ class GoogleFontCssInlineFilterSizeLimitTest
  protected:
   virtual void SetUp() {
     GoogleFontCssInlineFilterTestBase::SetUp();
-    // GoogleFontCssInlineFilter honors css_inline_max_bytes.
+    // GoogleFontCssInlineFilter uses google_font_css_inline_max_bytes.
     // Set a threshold at font_safieri, which should prevent longer
     // font_chromezilla from inlining.
-    options()->set_css_inline_max_bytes(STATIC_STRLEN("font_safieri"));
+    options()->set_google_font_css_inline_max_bytes(STATIC_STRLEN(
+        "font_safieri"));
     SetUpForFontFilterTest(RewriteOptions::kInlineGoogleFontCss);
   }
 };

net/instaweb/rewriter/public/css_inline_filter.h

@@ -21,6 +21,7 @@
 
 #include <cstddef>
 
+#include "net/instaweb/rewriter/cached_result.pb.h"
 #include "net/instaweb/http/public/semantic_type.h"
 #include "net/instaweb/rewriter/public/common_filter.h"
 #include "net/instaweb/rewriter/public/css_tag_scanner.h"
@@ -30,6 +31,8 @@
 #include "net/instaweb/util/public/basictypes.h"
 #include "net/instaweb/util/public/string.h"
 #include "net/instaweb/util/public/string_util.h"
+#include "pagespeed/kernel/html/html_element.h"
+#include "pagespeed/kernel/http/google_url.h"
 
 namespace net_instaweb {
 
@@ -75,6 +78,8 @@ class CssInlineFilter : public CommonFilter {
   // for semantics.
   virtual ResourcePtr CreateResource(const char* url, bool* is_authorized);
 
+  void set_size_threshold_bytes(size_t size) { size_threshold_bytes_ = size; }
+
  private:
   class Context;
   friend class Context;
@@ -87,7 +92,7 @@ class CssInlineFilter : public CommonFilter {
                     HtmlElement* element);
 
   const char* id_;  // filter ID code.
-  const size_t size_threshold_bytes_;
+  size_t size_threshold_bytes_;
 
   GoogleString domain_;
   CssTagScanner css_tag_scanner_;

net/instaweb/rewriter/public/rewrite_options.h

@@ -261,6 +261,7 @@ class RewriteOptions {
   static const char kFlushBufferLimitBytes[];
   static const char kFlushHtml[];
   static const char kFlushMoreResourcesEarlyIfTimePermits[];
+  static const char kGoogleFontCssInlineMaxBytes[];
   static const char kForbidAllDisabledFilters[];
   static const char kHideRefererUsingMeta[];
   static const char kIdleFlushTimeMs[];
@@ -608,6 +609,7 @@ class RewriteOptions {
   static const int64 kDefaultCssFlattenMaxBytes;
   static const int64 kDefaultCssImageInlineMaxBytes;
   static const int64 kDefaultCssInlineMaxBytes;
+  static const int64 kDefaultGoogleFontCssInlineMaxBytes;
   static const int64 kDefaultCssOutlineMinBytes;
   static const int64 kDefaultImageInlineMaxBytes;
   static const int64 kDefaultJsInlineMaxBytes;
@@ -1277,6 +1279,12 @@ class RewriteOptions {
   void set_css_inline_max_bytes(int64 x) {
     set_option(x, &css_inline_max_bytes_);
   }
+  int64 google_font_css_inline_max_bytes() const {
+    return google_font_css_inline_max_bytes_.value();
+  }
+  void set_google_font_css_inline_max_bytes(int64 x) {
+    set_option(x, &google_font_css_inline_max_bytes_);
+  }
   int64 js_inline_max_bytes() const { return js_inline_max_bytes_.value(); }
   void set_js_inline_max_bytes(int64 x) {
     set_option(x, &js_inline_max_bytes_);
@@ -3365,6 +3373,7 @@ class RewriteOptions {
   Option<int64> css_image_inline_max_bytes_;
   Option<int64> css_inline_max_bytes_;
   Option<int64> css_outline_min_bytes_;
+  Option<int64> google_font_css_inline_max_bytes_;
 
   // Preserve URL options
   Option<bool> css_preserve_urls_;

net/instaweb/rewriter/rewrite_options.cc

@@ -136,6 +136,8 @@ const char RewriteOptions::kFlushMoreResourcesEarlyIfTimePermits[] =
     "FlushMoreResourcesEarlyIfTimePermits";
 const char RewriteOptions::kForbidAllDisabledFilters[] =
     "ForbidAllDisabledFilters";
+const char RewriteOptions::kGoogleFontCssInlineMaxBytes[] =
+    "GoogleFontCssInlineMaxBytes";
 const char RewriteOptions::kHideRefererUsingMeta[] = "HideRefererUsingMeta";
 const char RewriteOptions::kIdleFlushTimeMs[] = "IdleFlushTimeMs";
 const char RewriteOptions::kImageInlineMaxBytes[] = "ImageInlineMaxBytes";
@@ -404,6 +406,8 @@ const int64 RewriteOptions::kDefaultCssInlineMaxBytes = 2048;
 const int64 RewriteOptions::kDefaultCssFlattenMaxBytes = 1024000;
 const int64 RewriteOptions::kDefaultCssImageInlineMaxBytes = 0;
 const int64 RewriteOptions::kDefaultCssOutlineMinBytes = 3000;
+// 3K is bigger than Roboto loader for Chrome (2.2k)
+const int64 RewriteOptions::kDefaultGoogleFontCssInlineMaxBytes = 3 * 1024;
 const int64 RewriteOptions::kDefaultImageInlineMaxBytes = 3072;
 const int64 RewriteOptions::kDefaultJsInlineMaxBytes = 2048;
 const int64 RewriteOptions::kDefaultJsOutlineMinBytes = 3000;
@@ -1196,6 +1200,13 @@ void RewriteOptions::AddProperties() {
       kCssFlattenMaxBytes,
       kQueryScope,
       "Number of bytes below which stylesheets will be flattened.", true);
+  AddBaseProperty(
+      kDefaultGoogleFontCssInlineMaxBytes,
+      &RewriteOptions::google_font_css_inline_max_bytes_, "gfci",
+      kGoogleFontCssInlineMaxBytes,
+      kQueryScope,
+      "Number of bytes below which Google Font stylesheets will be inlined.",
+      true);
   AddBaseProperty(
       kDefaultCssImageInlineMaxBytes,
       &RewriteOptions::css_image_inline_max_bytes_,

net/instaweb/rewriter/rewrite_options_test.cc

@@ -882,6 +882,7 @@ TEST_F(RewriteOptionsTest, LookupOptionByNameTest) {
     RewriteOptions::kFlushHtml,
     RewriteOptions::kFlushMoreResourcesEarlyIfTimePermits,
     RewriteOptions::kForbidAllDisabledFilters,
+    RewriteOptions::kGoogleFontCssInlineMaxBytes,
     RewriteOptions::kHideRefererUsingMeta,
     RewriteOptions::kIdleFlushTimeMs,
     RewriteOptions::kImageInlineMaxBytes,