Revert "[fuchsia] Allow system config to request Android-ish user agent OS."

This reverts commit f3dce521.

Reason for revert: We have no urgent need for this feature so removing
it in favour of introducing a caller (vs system) controlled API.

Original change's description:
> [fuchsia] Allow system config to request Android-ish user agent OS.
>
> Allow WebEngine to be configured to report an Android-like UserAgent
> via the system-provided config-data, to allow it to be fetch the right
> form of content for the device form-factor.
>
> This will likely be replaced with options to configure the Client Hints
> reported, on a per-instance basis, once those are standardized.
>
> Bug: b/171582703, 1010256
> Change-Id: I9db408be09ec9b9a78facc7b078d635b96c3637b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2522071
> Commit-Queue: Wez <wez@chromium.org>
> Commit-Queue: John Abd-El-Malek <jam@chromium.org>
> Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> Auto-Submit: Wez <wez@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#825042}

Bug: b/171582703
Bug: 1010256
Change-Id: If513affc89195fb78eafb1e9160e583b41708f38
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2574976
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834031}

fuchsia/engine/browser/web_engine_content_browser_client.cc

@@ -8,7 +8,6 @@
 #include <string>
 #include <utility>
 
-#include "base/command_line.h"
 #include "base/stl_util.h"
 #include "base/strings/string_split.h"
 #include "components/version_info/version_info.h"
@@ -103,22 +102,13 @@ std::string WebEngineContentBrowserClient::GetProduct() {
 }
 
 std::string WebEngineContentBrowserClient::GetUserAgent() {
-  std::string user_agent;
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kUseLegacyAndroidUserAgent)) {
-    user_agent =
-        content::BuildUserAgentFromOSAndProduct("Linux; Android", GetProduct());
-  } else {
-    user_agent = content::BuildUserAgentFromProduct(GetProduct());
-  }
-
+  std::string user_agent = content::BuildUserAgentFromProduct(GetProduct());
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kUserAgentProductAndVersion)) {
     user_agent +=
         " " + base::CommandLine::ForCurrentProcess()->GetSwitchValueNative(
                   switches::kUserAgentProductAndVersion);
   }
-
   return user_agent;
 }
 

fuchsia/engine/context_provider_impl.cc

@@ -169,7 +169,6 @@ bool MaybeAddCommandLineArgsFromConfig(const base::Value& config,
       switches::kForceMaxTextureSize,
       switches::kMaxDecodedImageSizeMb,
       switches::kRendererProcessLimit,
-      switches::kUseLegacyAndroidUserAgent,
       switches::kWebglAntialiasingMode,
       switches::kWebglMSAASampleCount,
   };

fuchsia/engine/switches.cc

@@ -19,7 +19,6 @@ const char kCorsExemptHeaders[] = "cors-exempt-headers";
 const char kEnableCastStreamingReceiver[] = "enable-cast-streaming-receiver";
 const char kCdmDataDirectory[] = "cdm-data-directory";
 const char kCdmDataQuotaBytes[] = "cdm-data-quota-bytes";
-const char kUseLegacyAndroidUserAgent[] = "use-legacy-android-user-agent";
 const char kDataQuotaBytes[] = "data-quota-bytes";
 
 }  // namespace switches

fuchsia/engine/switches.h

@@ -56,9 +56,6 @@ extern const char kCdmDataDirectory[];
 // Quota to apply to the CDM user data directory, in bytes.
 extern const char kCdmDataQuotaBytes[];
 
-// Enables reporting of an Android-like User Agent string.
-extern const char kUseLegacyAndroidUserAgent[];
-
 // Soft quota to apply to the Context's persistent data directory, in bytes.
 extern const char kDataQuotaBytes[];
 

fuchsia/engine/web_engine_integration_test.cc

@@ -71,7 +71,7 @@ class WebEngineIntegrationMediaTest : public WebEngineIntegrationTest {
   std::unique_ptr<media::FakeAudioConsumerService> fake_audio_consumer_service_;
 };
 
-class WebEngineIntegrationUserAgentTest : public WebEngineIntegrationTestBase {
+class WebEngineIntegrationUserAgentTest : public WebEngineIntegrationTest {
  protected:
   GURL GetEchoUserAgentUrl() {
     static std::string echo_user_agent_header_path =
@@ -81,8 +81,6 @@ class WebEngineIntegrationUserAgentTest : public WebEngineIntegrationTestBase {
 };
 
 TEST_F(WebEngineIntegrationUserAgentTest, ValidProductOnly) {
-  StartWebEngine(base::CommandLine(base::CommandLine::NO_PROGRAM));
-
   // Create a Context with just an embedder product specified.
   fuchsia::web::CreateContextParams create_params = DefaultContextParams();
   create_params.set_user_agent_product(kValidUserAgentProduct);
@@ -95,19 +93,12 @@ TEST_F(WebEngineIntegrationUserAgentTest, ValidProductOnly) {
       ExecuteJavaScriptWithStringResult("document.body.innerText;");
   EXPECT_TRUE(result.find(kValidUserAgentProduct) != std::string::npos);
 
-  // The UserAgent header should also include the desktop-ish Fuchsia
-  // platform & OS information, by default.
-  constexpr char kFuchsiaUserAgentContents[] = "(X11; Fuchsia)";
-  EXPECT_TRUE(result.find(kFuchsiaUserAgentContents) != std::string::npos);
-
   // Query & verify that the navigator.userAgent contains the product tag.
   result = ExecuteJavaScriptWithStringResult("navigator.userAgent;");
   EXPECT_TRUE(result.find(kValidUserAgentProduct) != std::string::npos);
 }
 
 TEST_F(WebEngineIntegrationUserAgentTest, ValidProductAndVersion) {
-  StartWebEngine(base::CommandLine(base::CommandLine::NO_PROGRAM));
-
   // Create a Context with both product and version specified.
   fuchsia::web::CreateContextParams create_params = DefaultContextParams();
   create_params.set_user_agent_product(kValidUserAgentProduct);
@@ -129,8 +120,6 @@ TEST_F(WebEngineIntegrationUserAgentTest, ValidProductAndVersion) {
 }
 
 TEST_F(WebEngineIntegrationUserAgentTest, InvalidProduct) {
-  StartWebEngine(base::CommandLine(base::CommandLine::NO_PROGRAM));
-
   // Try to create a Context with an invalid embedder product tag.
   fuchsia::web::CreateContextParams create_params = DefaultContextParams();
   create_params.set_user_agent_product(kInvalidUserAgentProduct);
@@ -138,8 +127,6 @@ TEST_F(WebEngineIntegrationUserAgentTest, InvalidProduct) {
 }
 
 TEST_F(WebEngineIntegrationUserAgentTest, VersionOnly) {
-  StartWebEngine(base::CommandLine(base::CommandLine::NO_PROGRAM));
-
   // Try to create a Context with an embedder version but no product.
   fuchsia::web::CreateContextParams create_params = DefaultContextParams();
   create_params.set_user_agent_version(kValidUserAgentVersion);
@@ -147,8 +134,6 @@ TEST_F(WebEngineIntegrationUserAgentTest, VersionOnly) {
 }
 
 TEST_F(WebEngineIntegrationUserAgentTest, ValidProductAndInvalidVersion) {
-  StartWebEngine(base::CommandLine(base::CommandLine::NO_PROGRAM));
-
   // Try to create a Context with valid product tag, but invalid version.
   fuchsia::web::CreateContextParams create_params = DefaultContextParams();
   create_params.set_user_agent_product(kValidUserAgentProduct);
@@ -156,25 +141,6 @@ TEST_F(WebEngineIntegrationUserAgentTest, ValidProductAndInvalidVersion) {
   CreateContextAndExpectError(std::move(create_params), ZX_ERR_INVALID_ARGS);
 }
 
-TEST_F(WebEngineIntegrationUserAgentTest, UseLegacyAndroidUserAgent) {
-  base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
-  command_line.AppendSwitch("use-legacy-android-user-agent");
-  StartWebEngine(std::move(command_line));
-
-  // Create a Context with both product and version specified.
-  fuchsia::web::CreateContextParams create_params = DefaultContextParams();
-  CreateContextAndFrameAndLoadUrl(std::move(create_params),
-                                  GetEchoUserAgentUrl());
-
-  // Query & verify that the UserAgent header echoed into the document body
-  // contains the legacy Android data.
-  constexpr char kLegacyAndroidUserAgentContents[] = "(Linux; Android)";
-  std::string result =
-      ExecuteJavaScriptWithStringResult("document.body.innerText;");
-  EXPECT_TRUE(result.find(kLegacyAndroidUserAgentContents) !=
-              std::string::npos);
-}
-
 // Check that if the CreateContextParams has |remote_debugging_port| set then:
 // - DevTools becomes available when the first debuggable Frame is created.
 // - DevTools closes when the last debuggable Frame is closed.